AudioNervosa

Systemic Development => Speakers => Topic started by: richidoo on December 07, 2016, 07:03:30 PM

Title: Line Arrays
Post by: richidoo on December 07, 2016, 07:03:30 PM
Getting bored with my current small woofer speakers. They sound great, but I want more bass. Turning them into 3 ways is not motivating me enough to get off my ass. Plutone kit is very appealing, but too expensive for a diy kit and they will still need subs and that is tricky. Legacy Focus at $7500 just a bridge too far right now, cuz my "beloved children" are sucking up the money like a sharknado! Cars, college, clothes, phones, WTF! Wife wants the big room back, for her big screen Hallmark, Tom Brady and Tucker Carlson TV, and entertaining friends and bizsociates, you know - normal human habitation. Can't blame her. I'd like those changes too, PLUS a huge underground sound studio. She also wants me to clean up my lab (formerly known as the game room) so she can have an office in there, and the room over the garage is destined for exercise equipment and ping ping table instead of a nice audio room. So I'm left with the smallest room in the house, besides the pantry and the bathrooms (I am grateful!) My daughter gave up piano lessons so the music room is freed up for audio room. It is warm and sunny, but very cozy @11W x 12L x 9H. I have played music in there before, but speakers were too big so I'm not sure how it "sounds." I like that it's small, I am like a den animal I like to be in a small box, alone with my music.

I've been rereading (again) the threads on diyaudio.com about line arrays using small full range drivers like Vifa TC9. I was interested in this topology ever since I saw the line array article years ago from John Murphy at http://trueaudio.com/array/
An expert speaker designer friend said I wouldn't be happy with the quality of the high frequency of array made from full range drivers so I skipped it. But the guys over on diy are convincing me that treble is good and to give it a try after all.

I think full height corner arrays would be perfect in the small room, conceptually at least! Reality has a tendency to spoil the best fantasies. Array requires EQ, probably digital to get the most out of it, with room correction, etc. But it's still crossover less speakers so I could still use tube amp if I want, it has nominal 101dB sensitivity at nominal 4 ohms, or I could make it 95dB at 16 ohms, good for tube amp. It takes up no floor space, good for small room. It has incredible low distortion bass, and they say it is supremely musical, as most tall speakers are. I am curious whether the treble will be very good or not, I am spoiled by a lot of great tweeters over the years, but the impulse measurements of the tall arrays posted on diyaudio.com suggest great treble performance, despite my common sense knee jerk tendency to wonder how the hell 64 tweeters in one room can be a good thing?  I know 64 woofers in one small room will be a very good thing.  :D

Who has heard tall arrays and what did you think? Ever heard corner arrays?

I heard the tall free standing Lingdorf arrays once, meh. Charlie always speaks highly of his arrays. I've heard a bunch of Selah arrays, both straight and curved CBT. But I'm not convinced that I've heard what is possible from a high end line array yet. The boys on diy say the EQ is critical to making it work well. That probably means a Windows PC at the heart of my system. Not thrilled with that. But it's not too expensive to try with these Vifa drivers that everyone says sounds soooo good. Your thoughts appreciated!

(http://www.diyaudio.com/forums/attachments/multi-way/521404d1451195824-corner-floor-ceiling-line-array-using-vifa-tc9-img_1797.jpg)
Title: Re: Line Arrays
Post by: HAL on December 07, 2016, 07:12:03 PM
Rich,
The room correction part can be very simple for file based replay. 

Math Audio Room EQ and a calibrated mic like a UMM-6 have worked very well in multiple settings now with the MS-3 running Foobar2000 and the dspMusik. 

Ran it for my Megaliths with just the BG Neo10's and 6x12 servo subs and worked exceedingly well.

I am a line array guy and finally back at it. 
Title: Re: Line Arrays
Post by: rollo on December 08, 2016, 07:37:11 AM
  Hey Richidoo the Pipes have 48 tweeters in da room. I love them but ,but, but they cannot reach their full potential in my room. Although a good sized room more room is really needed to get the huge sound stage they can offer.
   Then subs, a pair of OB servo babies. Ya just need room. For your Den/Cave if your in a DIY mode look at those little Audience drivers. If not ELAC and the integrated of your choice. Saving some green on the ELAC [ $500] put it into the front end.
    Or we have a pair of BG Radia FS 420 for sale.Small footprint. Knowing you though DIY is so much more inviting.  :-P


charles
Title: Re: Line Arrays
Post by: richidoo on December 12, 2016, 03:01:16 PM
I popped for 64 Vifa TC9 drivers from partsexpress. On sale for Christmas plus another $10 coupon, plus free shipping. Return shopping if I chicken out is about $100, so I guess I better not chicken out! 

I have the cabinets designed, and the room figured out. They will be floor to ceiling arrays, with 32 drivers each side. They will require EQ, probably dsp on PC.

They say as long as I sit 3 meters away, the combing should not be noticeable on music.

Bass is said to extremely clean and powerful with EQ.
Title: Re: Line Arrays
Post by: richidoo on December 13, 2016, 09:15:37 AM
I finished the plans today, at least first draft.

They are designed to live in the corner of the room, for best acoustic benefit.  There is a 2" face on each side, perp to the walls, this is to allow my 2" thick diffusor panels to meet the speaker edge smoothly. The front panel that will show is about a foot wide.

There is an inner box of 1/4" ply that the driver bolts to from the outside. Then there is a 1/8" spacer layer that surrounds the driver flange to make a surface for the 1/4" outer cosmetic layer to attach/removable. Each driver has it's own acoustic compartment, they are separated by 1/4" plywood. I will also put a small vertical dowel in the middle each compartment for stiffening the floor/ceiling of each compartment for low bass.

1/4 plywood doesn't seem strong enough for a speaker, but each compartment is very small, lots of reinforcement. Using PL urethane construction adhesive will be strong enough. Panel vibration and acoustic resonance should be very easy to damp. 3 sheets of 1/4" x 48 x 96 per speaker. The 9 foot tall vertical parts will be grafted together from 2 shorter pieces with 45 degree angled butt glue joint.

I had to hire my 16yo son the math genius to figure out the dimensions. I knew the shape and the dimension constraints, but changing any wall length has an exponential effect on the area so no easy way to calculate the other wall lengths accurately. He was able to make a formula for me to relate the front baffle width to the interior area, which is 61 sq in. Height of each chamber is 3", making 183 cu in volume, a little more than .1 cu ft, the recommended sealed volume. Subtract about 10 cu inches for the driver's own volume, the support dowel, and some interior box resonance treatment (dynamat, etc) should yield the target 172 cu in. (2.8 liter) The little drivers are very high Qts of .89, so small changes in the box volume have a small effect on the FR.

The 20Hz response of a single driver on a large baffle is about -30dB. Apparently there is enough linear Xmax available from this drivers to allow EQing them up to have flat response at 20Hz, but not very loud. 90dB at 20Hz would be awesome. The very small room will support low bass with "cabin effect." The corner placement cuts the radiating space in half compared to the curve on the datasheet. So it should be loud enough  when EQd to B&K curve or similar, which is -6dB at 20hz and 20kHz, peaking at 60Hz.

Anyway, Adding 30dB of EQ will require about 250W of power.  Some options for amps are Parallel-86 chip diy amps I have but not yet built, or the First One discreet diy amp that makes more power, or a class D amp. Or...
Title: Re: Line Arrays
Post by: BobM on December 13, 2016, 02:28:40 PM
Not to bust your bubble Rich, but in my experience line array's need to be out in the room, not in a corner. And they also like to be sitting face forward with little to no toe in.

Just sayin.
Title: Re: Line Arrays
Post by: richidoo on December 13, 2016, 03:12:06 PM
Thanks Bob! Don't worry my bubble not busted.

The corner position has some benefits that I want to try, but I can try a freestanding cabinet later, if I like the array sound.
Title: Re: Line Arrays
Post by: Nick B on December 13, 2016, 04:43:50 PM
Getting bored with my current small woofer speakers. They sound great, but I want more bass. Turning them into 3 ways is not motivating me enough to get off my ass. Plutone kit is very appealing, but too expensive for a diy kit and they will still need subs and that is tricky. Legacy Focus at $7500 just a bridge too far right now, cuz my "beloved children" are sucking up the money like a sharknado! Cars, college, clothes, phones, WTF! Wife wants the big room back, for her big screen Hallmark, Tom Brady and Tucker Carlson TV, and entertaining friends and bizsociates, you know - normal human habitation. Can't blame her. I'd like those changes too, PLUS a huge underground sound studio. She also wants me to clean up my lab (formerly known as the game room) so she can have an office in there, and the room over the garage is destined for exercise equipment and ping ping table instead of a nice audio room. So I'm left with the smallest room in the house, besides the pantry and the bathrooms (I am grateful!) My daughter gave up piano lessons so the music room is freed up for audio room. It is warm and sunny, but very cozy @11W x 12L x 9H. I have played music in there before, but speakers were too big so I'm not sure how it "sounds." I like that it's small, I am like a den animal I like to be in a small box, alone with my music.

I've been rereading (again) the threads on diyaudio.com about line arrays using small full range drivers like Vifa TC9. I was interested in this topology ever since I saw the line array article years ago from John Murphy at http://trueaudio.com/array/
An expert speaker designer friend said I wouldn't be happy with the quality of the high frequency of array made from full range drivers so I skipped it. But the guys over on diy are convincing me that treble is good and to give it a try after all.

I think full height corner arrays would be perfect in the small room, conceptually at least! Reality has a tendency to spoil the best fantasies. Array requires EQ, probably digital to get the most out of it, with room correction, etc. But it's still crossover less speakers so I could still use tube amp if I want, it has nominal 101dB sensitivity at nominal 4 ohms, or I could make it 95dB at 16 ohms, good for tube amp. It takes up no floor space, good for small room. It has incredible low distortion bass, and they say it is supremely musical, as most tall speakers are. I am curious whether the treble will be very good or not, I am spoiled by a lot of great tweeters over the years, but the impulse measurements of the tall arrays posted on diyaudio.com suggest great treble performance, despite my common sense knee jerk tendency to wonder how the hell 64 tweeters in one room can be a good thing?  I know 64 woofers in one small room will be a very good thing.  :D

Who has heard tall arrays and what did you think? Ever heard corner arrays?

I heard the tall free standing Lingdorf arrays once, meh. Charlie always speaks highly of his arrays. I've heard a bunch of Selah arrays, both straight and curved CBT. But I'm not convinced that I've heard what is possible from a high end line array yet. The boys on diy say the EQ is critical to making it work well. That probably means a Windows PC at the heart of my system. Not thrilled with that. But it's not too expensive to try with these Vifa drivers that everyone says sounds soooo good. Your thoughts appreciated!

(http://www.diyaudio.com/forums/attachments/multi-way/521404d1451195824-corner-floor-ceiling-line-array-using-vifa-tc9-img_1797.jpg)


Hey Rich,
I'm looking forward to your new speakers. Sorry you didn't get the plutonium ones ☠️ I'm living vicariously thru you and others as my car just died and is resting peacefully at the junk yard. Heck, it's only money 😭
Nick
Title: Re: Line Arrays
Post by: richidoo on December 13, 2016, 06:17:59 PM
Thanks Nick. I'm waiting on my son to finish finals (tomorrow) and bring the minivan home so I can go buy the wood to get started.

I was thinking about the Plutone today, I still want to try that next. It'll take a year or more to get through this array project. I should be ready for Plutone by then.

Sorry to hear about the car... RIP
Hope your new car rocks your world!
Title: Re: Line Arrays
Post by: richidoo on December 16, 2016, 06:35:56 AM
The drivers arrived yesterday. One box packed at the chinese factory with 45 drivers, and another partial box with 20 drivers packed at PE.

Ummm, that's one too many!  :D   :thumb:

I have 45 days to test them all with impedance sweep to filter out any defects.

Today my minivan is back home so I plan to go buy the six sheets of 1/4" plywood.
Title: Re: Line Arrays
Post by: mresseguie on December 31, 2016, 03:57:49 AM
I was going to just lurk in this thread to learn and get educated, but then you twice made mention of the Plutone speakers. I just spent the last two days pouring over all the info the Tony Gee has about his Plutone speakers.

I'll post the rest of my thoughts in the Plutone thread rather than hijacking this thread.




Title: Re: Line Arrays
Post by: richidoo on December 31, 2016, 03:55:53 PM
Hey Michael, are you back home in Taiwan now?

I was sooo hot for those Plutones in the summer. I still might like to build them for the new re-repurposed living room. But the price, holy shit!  Each time I think to "give in and just buy them," I convert the price to dollars and I say forget it. Dollar has been rising lately, and he hasn't raised his prices yet.

I was thinking about them today, that the 8008 driver has high Qms of 10, so it is very low self damping. This makes it very revealing, fast, alive, all the things we like, but a high Qms relies on the amplifier for electrical damping, that means solid state amplifier. Tube amps offer speakers relatively poor damping and do better when the driver can better damp itself (lower Qms.) I was thinking of running Plutone with Don Sachs amp. But Modulus-86 might be a better match.

Also check out Troels Gravesen's new take (http://www.troelsgravesen.dk/8008-CORNER.htm) on the AudioNote speaker riff. Plutone is voiced to play away from the wall, Troels needs corner placement. But Tony certainly pushed Troels towards a simpler crossover network than what Troels typically does.

I got my new sound room mostly cleaned out of clutter, it feels pretty nice in there. I'll try listening in there with the Kairos speakers next week.

So it's time to start building the cabinets. I've been such an audio delinquent recently I wonder if I can still build new speakers anymore? I want to make them from sheet metal, but I feel I should do a rough pass in masonite to make sure I like the sound, etc. But it's a lot of work, so I might just do it once in metal. Depends on the parts quote from local custom sheet metal shop.
Title: Re: Line Arrays
Post by: Bob in St. Louis on January 01, 2017, 02:44:09 PM
Looking forward to seeing some pics of this one.
Sounds pretty cool Rich!
Title: Re: Line Arrays
Post by: steve on January 01, 2017, 06:15:28 PM
Rich, good luck on your project. Can't wait to see how it turns out.


Cheers

Steve

 
Title: Re: Line Arrays
Post by: richidoo on January 01, 2017, 09:34:01 PM
Thanks for the encouragement fellas. I will post some pics.
Title: Re: Line Arrays
Post by: steve on March 02, 2017, 09:48:38 PM
Thanks for the encouragement fellas. I will post some pics.

Just wondering how things, any tests, are going Rich?

Cheers

Steve
Title: Re: Line Arrays
Post by: richidoo on March 03, 2017, 07:36:15 PM
Thanks so much for caring to ask, Steve!   :D 

Yeah, it's coming along slowly. I ordered driver mounting parts this week, 256 screws and T-nuts.  Pity the poor bastard who has to assemble it all! I tweaked the design a little, made the baffle narrower, footprint more square. It's final now. I bought the lumber, figured out the cutting plan. Waiting on weather, schedule and my energy to coincide to begin.

I plan to use my Neurochrome Audio Parallel-86 composite chip amps based on LM4780 and LM49710 ICs which share a feedback loop. I still have to build them. They are the high-power version of the Modulus-86 amps I have and love. They make 120W>4R with extremely low THD all the way to max power. It should be enough.

More to come
Title: Re: Line Arrays
Post by: Bob in St. Louis on March 03, 2017, 07:46:17 PM
Thanks for the encouragement fellas. I will post some pics.
Bump.  8)
Title: Re: Line Arrays
Post by: steve on March 16, 2017, 09:09:39 PM
Thanks so much for caring to ask, Steve!   :D 

Yeah, it's coming along slowly. I ordered driver mounting parts this week, 256 screws and T-nuts.  Pity the poor bastard who has to assemble it all! I tweaked the design a little, made the baffle narrower, footprint more square. It's final now. I bought the lumber, figured out the cutting plan. Waiting on weather, schedule and my energy to coincide to begin.

I plan to use my Neurochrome Audio Parallel-86 composite chip amps based on LM4780 and LM49710 ICs which share a feedback loop. I still have to build them. They are the high-power version of the Modulus-86 amps I have and love. They make 120W>4R with extremely low THD all the way to max power. It should be enough.

More to come

I think I can understand Rich. It does take time and better to do a job well than half way.

We are still very interested in the results of your project.

Cheers

Steve
Title: Re: Line Arrays
Post by: richidoo on April 09, 2017, 08:37:49 PM
I cut all the wood parts for the speaker cabinets. I have all the parts on hand now. Need to cut driver holes in the baffle and drill the internal wiring holes then I'm ready for glue up. I'll post some pics soon.
Title: Re: Line Arrays
Post by: richidoo on April 12, 2017, 10:45:11 AM
Pics:
1. Raw 4x8x .160" "Ecoboard" hardboard from Brazil via Home depot (3/16" nominal)

2. Setting up to cut the big sheets down to size. The 2x4s lift the boards up off the ground for blade clearance.

3. Ready to cut. A 4' level makes a good fence.

4. Sheets stacked. The tall ones will be sliced into thinner strips to make the array walls. The short ones are cut up into 8x8 squares to make the chamber separating/reinforcing panels that go inside the box.

5. Halfway setup to cut the array side wall panels.

6. Custom jig to cut the front baffle angle from the 8" square internal braces.  See my trash can outfeed supports?

7. Array sides stacked up inside. Ready for gluing. The side panels have 45 degree miter edges on one side, and the front baffle strips have mirrored 45 degree miters on both long edges. That was a bit of a cluster to setup the cut because once one edge is miter cut then the sharp edge doesn't slide easily along the fence, it wants to slide under the fence edge. So I had to make a custom fence that extended down into a miter groove below the saw surface. The parts aren't perfect, but they bend pretty easily a little, so I think it'll work out.

8. 64 internal braces stacked. They are all virtually identical thanks to the jig. Ready for drilling 5 small holes in each for the hookup wiring.

Still do do: cut the driver holes with 3" hole saw (perfect size)
drill the mounting screwholes in the baffles
glue on the T nuts to the inside of the baffles
glue up the boxes
Flush trim the boxes to final shape
sand, paint, wire and mount drivers

Two boxes 54" each which will stack floor to make the ceiling height of ~9'.
Title: Re: Line Arrays
Post by: rollo on April 17, 2017, 04:29:16 PM
Ain't no stopping you now go get em richidoo. Sounds interesting keep it coming

charles
Title: Re: Line Arrays
Post by: steve on April 29, 2017, 08:54:16 AM
Pics:
1. Raw 4x8x .160" "Ecoboard" hardboard from Brazil via Home depot (3/16" nominal)

2. Setting up to cut the big sheets down to size. The 2x4s lift the boards up off the ground for blade clearance.

3. Ready to cut. A 4' level makes a good fence.

4. Sheets stacked. The tall ones will be sliced into thinner strips to make the array walls. The short ones are cut up into 8x8 squares to make the chamber separating/reinforcing panels that go inside the box.

5. Halfway setup to cut the array side wall panels.

6. Custom jig to cut the front baffle angle from the 8" square internal braces.  See my trash can outfeed supports?

7. Array sides stacked up inside. Ready for gluing. The side panels have 45 degree miter edges on one side, and the front baffle strips have mirrored 45 degree miters on both long edges. That was a bit of a cluster to setup the cut because once one edge is miter cut then the sharp edge doesn't slide easily along the fence, it wants to slide under the fence edge. So I had to make a custom fence that extended down into a miter groove below the saw surface. The parts aren't perfect, but they bend pretty easily a little, so I think it'll work out.

8. 64 internal braces stacked. They are all virtually identical thanks to the jig. Ready for drilling 5 small holes in each for the hookup wiring.

Still do do: cut the driver holes with 3" hole saw (perfect size)
drill the mounting screwholes in the baffles
glue on the T nuts to the inside of the baffles
glue up the boxes
Flush trim the boxes to final shape
sand, paint, wire and mount drivers

Two boxes 54" each which will stack floor to make the ceiling height of ~9'.

Sounds like you have all under control Rich. I wish I could even approximated being as good as you when it comes to wood working.

My simple large box for my test speakers were done by a professional, who still has all ten digits.  :rofl:

Cheers
Steve

Title: Re: Line Arrays
Post by: richidoo on May 08, 2017, 01:28:52 PM
Baffle holes cut today, 64 in all. Will need a new 3" hole saw after this.  :D
Title: Re: Line Arrays
Post by: Tinnitus Towers on May 09, 2017, 07:16:55 AM
Hi,
I saw your post about your corner loaded line arrays and it made me join the forum :D

I recently built a set of line arrays Towers using the wonderful TC9s and modeled after Roger Russell's IDS-25. His array is 25 drivers tall, wired with 5 groups of 5 wired parallel and all groups together in series, and sells for $18,000  :shock:

I wired my array with 23 drivers per side (basement ceiling constraints) with 8 drivers in parallel and 3 sets in series. I made a dummy driver by using an 8 ohm resistor since I would be 1 driver short of the 8x3 configuration.

The forum member from diyaudio.com named wesayso, I saw you mentioned him in your post, he used insulation as a stuffing material and I wish I had. I only lined the walls with acoustic foam and think I could have gotten a few hz lower with insulation fully stuffed. Oh well, just more work for me to do later.

I made my Towers out of 3/4" mdf and they are 5.5"x 11.5"x78.5" without the bases which add about 1.75". They are simple rectangles for the ease of construction. I used a 3" hole saw as well but the one I was using didn't quite make the holes big enough by about 1/32" maybe 1/16". So, I had to take my dremel and sand each hole with a sanding bit to get all of the drivers to fit. I have bracing every 4 drivers since I didn't think there would be much flex for how thick these are compared to the tiny full range woofers. I assembled them with crimp terminals (huge time saver) and slapped some ribbon stripe mahogany veneer from veneersupplies.com (best place for veneer BTW) and bam had some very nice towers. Overall build probably costs about $800.

Listening impressions: just to give you even more motivation to finish these.... best speakers I have built to this day! Once you listen to a line array you will be addicted to them for life. The absolute lack of distortion is mind blowing, at any volume. Mine need big EQ down low but that may be from my room being a terrible audio environment. Around 20db is what I was working with to get +3db over flat in the bass region. I was using a inuke 3000 to drive them and was running out of headroom quick... the bass sounded so smooth with the line arrays and it's almost a mind trick hearing this clear bass coming from such small drivers. Mind range is excellent and the highs are so nice to listen to that I experience no listening fatigue whatsoever. I sometimes fall asleep when listening to these speakers for an extended period of time. I do not see myself building any more point source speakers in the future unless they are for someone else.

However, since I was running out of headroom with so much EQ in the low end and not wanting to constantly dump all that power on the TC9 voice coils, I decided to make a pair of stereo subwoofers to handle the low end. I mean, it's what they were designed to do... so I picked up 2 15" Dayton HF subwoofers from parts express when they were on sale and built some big sealed boxes for them. 18"x18"x23" with 3/4" mdf walls and double thick baffle for 1.5". Fully stuffed with insulation (after making that mistake with the towers). I cross them at about 200 hz with a 8db shelf filter boost and I am so glad I did. Now I have the power to blast new age songs and the only lights that come up on my amp are for the subs. The TC9s shall live a long life! I was surprised how well the stereo subs blend with the mains, I don't even realize they are there. I initially tried pairing the towers with a BIC F12 sub I have but it took away from the stereo imagining. I am not at all disappointed with this set up and have no reason to ever replace my mains again. (My subs are still unfinished but will probably receive the same Beene as the towers) I am using a minidsp 2x4 HD for processing.

I assure you that you will love your Towers, whether they are in the corner or out in the open. If you have any questions, I can try to answer them, but I'm only 23 so somewhat a noob at audio but I have a good idea. I am using a minidsp 2x4 HD for processing with PEQ only. FIR is yet to come.

Didn't want to jack your post, but I just wanted to share how well your towers are going to turn out.
Title: Re: Line Arrays
Post by: rollo on May 09, 2017, 08:09:20 AM
  Wow cool stuff guys.

charles
Title: Re: Line Arrays
Post by: richidoo on May 09, 2017, 11:03:09 AM
Hi,
I saw your post about your corner loaded line arrays and it made me join the forum :D

Welcome to AudioNervosa Tinnitus Towers!! Thanks for describing your system and how much you like it. That is inspiring to me, thanks. I've heard a few multiway arrays, never really been impressed with them, but they were all passive crossover 2 ways. I've had the urge to build these full rangers since I saw John Murphy's design.  But I'm glad I waited until TC9s became popular. Charles (rollo, posted above) has Pipedream line arrays he always raves about them, so that's another inspiration to trying these.

Quote
I wired my array with 23 drivers per side (basement ceiling constraints) with 8 drivers in parallel and 3 sets in series. I made a dummy driver by using an 8 ohm resistor since I would be 1 driver short of the 8x3 configuration.

That is clever idea, the extra resistor.  :thumb:

Quote
The forum member from diyaudio.com named wesayso, I saw you mentioned him in your post, he used insulation as a stuffing material and I wish I had. I only lined the walls with acoustic foam and think I could have gotten a few hz lower with insulation fully stuffed. Oh well, just more work for me to do later.

I'm not sure what I'm going to do about acoustic damping yet. I already have large enough volume, full .1 sf each, so I don't need full stuffing to increase apparent volume. Boosting bass electronically simulates lower Q that you would get from more stuffing anyway, so that's moot. We only need to be concerned with impedance blips that might affect FR. fluid's recent impedance plot with no stufffing looked pretty harmless to me so I'm not worried about it. I prefer minimal damping of the cone motion, to maximize transient response, so I would use only a little stuffing, if any. Lots of stuffing increases friction of the air moving through the stuffing, on the inhale and exhale. So the stuffing prevents free motion of the cone, dulling transients, robbing the feeling of life from the music. I'm not so concerned with minor impedance bumps if I have very strong electrical damping in the amp (low output impedance amp) and dsp to correct the bad FR bumps. The impedance bumps come from acoustic reflections inside the cabinet. That can only happen at wavelengths equal or smaller than the inside box dimensions. Below that freq it is just standing wave, pressure pulse, no reflections, no resonance, no impedance blip. My drivers each have their own chamber ~3" tall, so reflection wavelengths are very small, 8" is the largest and the one I'm concerned about, that makes fundamental resonance at 1700Hz. That should be easily damped with 1" FG or cotton on the reflection surfaces.  The 3" vertical height of each chamber resonates at 4500Hz. I guess that's more of a concern and I should think more about that. I'll experiment with it in a mock up box. Thanks for raising that. 1/4 foam or cotton insulation should kill that enough.

Quote
I used a 3" hole saw as well but the one I was using didn't quite make the holes big enough by about 1/32" maybe 1/16". So, I had to take my dremel and sand each hole with a sanding bit to get all of the drivers to fit.

My hole saw is Milwaukee brand, it cuts a hair too big, so perfect fit for TC9, lays flat, no wobble. I did a test hole a few months ago before the main run. Lots of work cutting all those holes!


Quote
I assembled them with crimp terminals (huge time saver)

Where did you get the terminals and what sizes did you use? I've been thinking about doing that, but my audionervosa perfectionism drives me toward soldering. I always thought that a dab of silver conductivity paste like Walker SST or similar should make slide on terminals work as well as solder. What do other ANs think about this?

Quote
and slapped some ribbon stripe mahogany veneer from veneersupplies.com (best place for veneer BTW) and bam had some very nice towers. Overall build probably costs about $800.

I bookmarked that link for future reference. My build cost a little more with the more drivers, but similarly cheap. I like that!

Quote
Listening impressions: just to give you even more motivation to finish these.... best speakers I have built to this day! Once you listen to a line array you will be addicted to them for life. The absolute lack of distortion is mind blowing, at any volume.

That's awesome. I can't wait to hear mine. Part of the reason I'm trying these is cuz people said how great the bass is, and they can play loud without getting edgy. I love to play modern symphonies and big bands really loud, reminds me when I used to sit in the orchestra playing trumpet. But I'm tired of paying 10k for speakers that can handle it without distortion (they still do distort anyway - so how much do I have to pay? Hence DIY, and hence line array with huge headroom and low distortion.

Quote
Mine need big EQ down low but that may be from my room being a terrible audio environment. Around 20db is what I was working with to get +3db over flat in the bass region.

That's about right, judging from FR measurements of the uncorrected array, like wesayso. But 20dB boost is a lot of power. I think he figured he needed 250W to push his array to linear Xmax. You want headroom in the amp too, like you said. Since this is full range you don't want to listen to inexpensive class D amp playing at full power trying to play bass and treble at same time. The amp distortion rises near max power and makes the mids and treble sounds very distorted. I'm installing my arrays in a pretty small room, and in corner mounted, so there will be a lot of LF room gain. I'm going to start with NeuroChrome Parallel-86 (https://www.neurochrome.com/parallel-86/) chip amp because I love the sound of the Mod-86 design and I already have the PCBs and chips. It makes 120W>4. My wiring will make 4 ohms load. If that's not enough power, maybe NCore 500, like Nord. Or a custom DIY amp from my local friend Sol.

Quote
I was using a inuke 3000 to drive them and was running out of headroom quick... the bass sounded so smooth with the line arrays and it's almost a mind trick hearing this clear bass coming from such small drivers. Mind range is excellent and the highs are so nice to listen to that I experience no listening fatigue whatsoever. I sometimes fall asleep when listening to these speakers for an extended period of time. I do not see myself building any more point source speakers in the future unless they are for someone else.

That's what I'm hoping for too. I don't want to notice the speakers, I don't want to hear the "details." I just want the music fully exposed for me to choose how I listen at any moment. I don't want to be held hostage to the sound quality by speakers.

Quote
However, since I was running out of headroom with so much EQ in the low end and not wanting to constantly dump all that power on the TC9 voice coils, I decided to make a pair of stereo subwoofers to handle the low end.

TC9 voice coils can handle the distributed power no problem, but 3" drivers will always have limited acoustic impedance, no matter how many in a straight line, it's still only 3" wide and the air molecules can easily get away from that small cone when it is accelerating so slowly at LF. Only large driver cone can grip the air firmly at LF. The air in the middle of big cone can't escape. So bass detail is always better with larger diameter drivers.

wesayso feels the need for subs for his HT use, maybe for more LF volume in his big room. But he said it's OK without subs for music. I think once he gets the subs playing he will like them for music too, because bass detail, slam and tonal balance at very low volumes will all be much better. Adding that bottom octave makes such a huge difference in music listening, especially at low volume, late night listening. I'm doing this to move my primary solitary deep dive listening excursions out of the main family room of the house and into a small door closable room, officially named "the weird room." I want to be able to listen to a symphony at 3am if I can't sleep, and I want to hear the bass cuz that's what it's all about. So I may end up adding subs later too. I have 3 of the 6 walls in the weird room are exterior walls, so I might do a few infinite baffle subs in there for distributed bass. But Maybe the arrays will be enough.

Quote
I mean, it's what they were designed to do... so I picked up 2 15" Dayton HF subwoofers from parts express when they were on sale and built some big sealed boxes for them. 18"x18"x23" with 3/4" mdf walls and double thick baffle for 1.5". Fully stuffed with insulation (after making that mistake with the towers). I cross them at about 200 hz with a 8db shelf filter boost and I am so glad I did. Now I have the power to blast new age songs and the only lights that come up on my amp are for the subs. The TC9s shall live a long life! I was surprised how well the stereo subs blend with the mains, I don't even realize they are there. I initially tried pairing the towers with a BIC F12 sub I have but it took away from the stereo imagining. I am not at all disappointed with this set up and have no reason to ever replace my mains again. (My subs are still unfinished but will probably receive the same Beene as the towers) I am using a minidsp 2x4 HD for processing.

Sounds like a great setup. I agree stereo subs needed for high end music playback, especially acoustic music where LF acoustic information is very much in stereo.

Quote
I assure you that you will love your Towers, whether they are in the corner or out in the open. If you have any questions, I can try to answer them, but I'm only 23 so somewhat a noob at audio but I have a good idea. I am using a minidsp 2x4 HD for processing with PEQ only. FIR is yet to come.

Thanks, I may take you up on that as I try to get mine working. You have a lot of audio knowledge for a young person, sorry don't mean to sound condescending, but it is with respect. I'm a young person too, never grew up! Do you have electronics background?

Quote
Didn't want to jack your post, but I just wanted to share how well your towers are going to turn out.

You are welcome to hijack any thread you want here at AN, that's what we're here for. Everyone has something valuable to add. There's no cliques here. All constructive posts are welcome.
Thanks again!
Rich
Title: Re: Line Arrays
Post by: Bob in St. Louis on May 09, 2017, 04:12:15 PM
Welcome to the sickness!  :thumb:
Title: Re: Line Arrays
Post by: Tinnitus Towers on May 09, 2017, 07:41:09 PM
Quote from: richidoo
Lots of stuffing increases friction of the air moving through the stuffing, on the inhale and exhale. So the stuffing prevents free motion of the cone, dulling transients, robbing the feeling of life from the music. I'm not so concerned with minor impedance bumps if I have very strong electrical damping in the amp (low output impedance amp) and dsp to correct the bad FR bumps. The impedance bumps come from acoustic reflections inside the cabinet. That can only happen at wavelengths equal or smaller than the inside box dimensions.

I only say I regret not using insulation to stuff them is from the many impedance sweep tests that wesayso took from his tiny test woofer enclosure. Its hard to find with the forum being over 200 pages :shock:. There was a small bump he found, being very small but still there, and the insulation gave the best sweep to eliminate it. Considering how small of Xmax the TC9 has and with so many drivers, I don't think the pressure of the cabinet will be much of an issue or air friction. All speculation...

Quote from: richidoo
Where did you get the terminals and what sizes did you use? I've been thinking about doing that, but my audionervosa perfectionism drives me toward soldering. I always thought that a dab of silver conductivity paste like Walker SST or similar should make slide on terminals work as well as solder.

As a huge fan of parts express, I get all of my speaker components there I can, which would include the crimp terminals. The terminal sizes of the TC9 are .110" (3/32") and 3/16". They come in packs of 50 pcs for under $5! I used 18 AWG wire throughout with two wires going to each crimp. The crimps were size 14-16 and two 18 AWG wires fit perfectly. If I ever had a crimp with only one wire going to it then I would just strip twice as much jacketing off and fold it over to be the same amount of copper strands as 2 wires if that makes sense.

Quote from: richidoo
I bookmarked that link for future reference (veneersupplies.com).

Seriously best site for veneering. He is named Joe the Woodworker and has a bunch of guides of how to apply different veneers to different substrates and all of his glues and tools are better than anything else on the market. After buying raw zebrawood and paper backed ribbon stripe mahogany, I like the paper backed a lot more. So much easier to get flat and you can use contact cement with it! His contact cement has wonderful reviews. I have only gotten to trying cold pressing and reactivating regular titebond wood glue with an iron. Ironing is easier between the two.

Quote from: richidoo
I just want the music fully exposed for me to choose how I listen at any moment. I don't want to be held hostage to the sound quality by speakers.

The thing I like about the minidsp 2x4 HD is that it has 10 PEQ bands on both input and output channels. So, I EQ'd flat with the output channel PEQ and X-over. This way I can use the PEQ on the inputs to apply any house curve I desire. I checked my configuration and X-over point is actually closer to 300 hz. I attached the PEQ I have on the towers for a reference of what you are looking at before the low end boost and to show you how poor my room is since the TC9 has a pretty flat response. My digital processing experience is extremely limited, about 3 months...

Quote from: richidoo
TC9 voice coils can handle the distributed power no problem, but 3" drivers will always have limited acoustic impedance, no matter how many in a straight line, it's still only 3" wide and the air molecules can easily get away from that small cone when it is accelerating so slowly at LF. Only large driver cone can grip the air firmly at LF. The air in the middle of big cone can't escape. So bass detail is always better with larger diameter drivers.

I may make 2 miniDSP profiles to be able to switch from full range and with subs. What you said is great insight of how low frequencies work better with larger drivers, very interesting.

Quote from: richidoo
Do you have electronics background?

Not really. My degree is in Mechanical Engineering and both of my grandpas have very good woodworking skills. One of them has made all of the furniture in my bedroom out of maple and cherry. So, after using my dad's old JVC Zero 5's with real ribbon tweeters, I wondered if I could build some speakers. They have woodworking, engineering, and something that will last forever(justifying the cost) all in one package. So, that's how I got started. Learned a lot along the way and the hard part is trying to explain it to other people and make it sound interesting!  :rofl:
Title: Re: Line Arrays
Post by: richidoo on May 10, 2017, 08:49:21 PM
I drilled all the screw holes today. twhs

My daughter asked me "why I'm putting so many holes in that wood?" It was easy to satisfy her curiosity ("moar speakers,"  :roll: ) but far more difficult to answer that same question for myself. This used to be about Stan Kenton and Antonin Dvorak. What is it about now?

Which led to further contemplation:
Staying in the safe zone: How crazy can I get before I notice that I'm crazy?
Going beyond the event horizon: How crazy is too crazy to know I'm crazy?
What happens inside the speaker building black hole? Do I really want to know?
Title: Re: Line Arrays
Post by: tmazz on May 11, 2017, 07:53:42 AM
How crazy is too crazy to know I'm crazy?

Rich we all passed that point a long time ago.  :rofl:
Title: Re: Line Arrays
Post by: steve on May 11, 2017, 07:54:15 AM
If I may add something to the conversation that might help.

I have recently been testing the effects of wire gauge on "sound" of my test speakers. But it has not been one solid wire, but multiple wires of 18 gauge in parallel. The reason will become apparent.

What I have found, which correlates with theory, is that there appears to be an optimum gauge which produces the most accurate/natural sound over the entire audio spectrum.

With my speakers, increasing the gauge by paralleling more 18 gauge wires was beneficial to a certain point. Beyond that point is questionable. Depending upon the speaker type, the optimum gauge will depend upon the speaker type.

Several points are accomplished by paralleling. First, the size is increased, less resistance, so damping factor is increased. A little can mean a lot. The voices will also flesh out due to the lower midrange/upper bass minimum impedance being less important  (cone types with varying impedance), but up to a point.

Besides the low end being addressed, the inductance of the wire at high frequencies is substantially reduced, thus a little more highs. In my case, the inductance is reduced by approximately 10 times.

In conclusion, with too few wires in parallel, the highs can drop off, and the bass damping factor less. With too large of wire, the bass damping and lower midrange may become excessive, causing masking, and more highs.  I have found the right gauge maximizes flatness in response in my speakers.

Cheers and I hope this possibly helps with adjusting your speakers. If it does not, no sweat Rich.

Steve
Title: Re: Line Arrays
Post by: richidoo on May 11, 2017, 11:01:18 AM
Nice post Steve, thanks.

I have 100ft of silver plated copper teflon insulation to use for hookup wire in these arrays. I think it is either 14 or 16 ga.

Each driver has it's own sealed chamber, so wiring passes through pre drilled holes in the chamber separator panels, so no opportunity to makes changes after initial assembly. Attached pic is the wiring diagram and a study to figure out how many holes to drill in each chamber panel. I'll go for a squeeze fit to avoid caulking.

There is a lot of series wired drivers to increase resistance, and a lot of voice coil inductance but it's "the load" so that doesn't seem to bother the sound according to those who have gone before. It will be interesting to measure the array.
Title: Re: Line Arrays
Post by: richidoo on May 11, 2017, 11:20:36 AM
Might as well post the final version of the plans as it changed a little.

The tall front view is bottom half of one array. The top half is identical and sits on top, but inverted. Both screwed to wall and wired together.

I changed the plan to reduce the width of the front baffle, to reduce the distance from driver to the change in wall angle, which when too wide affects the sound noticeably, according to those who have gone before. I guess it's like having a concave kink inside a horn, causes a defraction or something. The edge of diffusion "BAD panels" will line up with the baffle edges to eliminate the convex speaker edges. 

This shape allows me to try it in my current listening room also.
Title: Re: Line Arrays
Post by: steve on May 11, 2017, 04:20:06 PM
Nice post Steve, thanks.

I have 100ft of silver plated copper teflon insulation to use for hookup wire in these arrays. I think it is either 14 or 16 ga.
................

There is a lot of series wired drivers to increase resistance, and a lot of voice coil inductance but it's "the load" so that doesn't seem to bother the sound according to those who have gone before. It will be interesting to measure the array.

I am not sure that the series wires will be a huge problem Rich.
In my latest experiment, I am using some 3 feet of single 18 gauge wire between xover and mid/tweeters (I don't wish to disassemble the speakers, at least not right now),

and 6 feet from amps to speaker posts, which is what I am paralleling. Testing with just the 6 foot length made a sonic difference with my speakers.

It would be neat to see if paralleling two or more wires makes a noticeable difference verses just one. (I know I am being a little selfish, but I always love an experiment.) (I also wish the modify would last longer so I can correct my English.)

Anyway, looking forward to your results Rich. :)

Cheers
Steve
Title: Re: Line Arrays
Post by: richidoo on May 11, 2017, 05:09:59 PM
I remember that I once paralleled different kind of wires for SCs. I think it was anticables solid transformer wire + 12ga zip cord ("RCA" brand chinese made clear vinyl insulated speaker wire from Home Depot.) It sounded pretty nasty. Either was better by itself, and that's really saying something for the zip cord. :)  I think I never did parallel two runs of the same wire.
Title: Re: Line Arrays
Post by: steve on May 11, 2017, 08:44:42 PM
I remember that I once paralleled different kind of wires for SCs. I think it was anticables solid transformer wire + 12ga zip cord ("RCA" brand chinese made clear vinyl insulated speaker wire from Home Depot.) It sounded pretty nasty. Either was better by itself, and that's really saying something for the zip cord. :)  I think I never did parallel two runs of the same wire.


I found the same results when mixing stranded wire with solid wire. Just does not sound right. I parallel the same brand solid wire, much much better, up to a point.

For all DIYers. If one has a frequency counter, signal generator, and scope, or a friend who has the equipment, one can match the inductors to the nearest turn. 0,5% capacitance meter match the capacitors.

(One can order a frequency counter for $7.50, which includes shipping. But one must know soldering and able to identify and match parts to the board labeling. There is no schematic or instruction manual. Minimum signal for the counter is approx. 2vrms and maximum input is 7vp-p.)

http://www.ebay.com/itm/like/122251535734

Just some thoughts that might help.

Cheers and looking forward to your speakers completion and review.

Steve


My ending last post I meant looking forward to how your speakers sound, not necessarily the experiment.
Title: Re: Line Arrays
Post by: tmazz on May 12, 2017, 07:51:33 AM
I never doubled up on any internal wiring, but I can tell you that about 6 years ago I upgraded my speaker cables from MIT MH-750 to MH-750 Shotgun cables. Both sets were late 80s vintage and unlike some of the later models with the word Shotgun in the name, these Shotgun cables were two pieces of the standard 750 cable wired together to form a single cable. I bought them not really because I wanted an upgrade, but rather because some system rearrangements lead to the need for shorter cables and I found these for a good price and grabbed them. And although the orgignal goal was to get shorter as opposed to better cables, I was very impressed with the amount of SQ increase that I got with the Shotguns.

So for what it's worth, at least sometimes, parallel runs of wire can be beneficial, but like everything else in this hobby, YMMV.
Title: Re: Line Arrays
Post by: steve on May 13, 2017, 07:50:57 PM
So for what it's worth, at least sometimes, parallel runs of wire can be beneficial, but like everything else in this hobby, YMMV.

Agreed T. Another example; if the system were a shade thin/lean, I would try one large gauge wire. This would provide a touch of inductive reactance to lower the signal as it rose in frequency, thus tending to negate the thinness/leanness. It would also allow for maximum bass and lower midrange, adding a little more flesh to the voices.

I know it is kind of a tone control, but with no adjustments on a system, it could be helpful.

Cheers
Steve
Title: Re: Line Arrays
Post by: Bob in St. Louis on May 13, 2017, 08:32:05 PM
So for what it's worth, at least sometimes, parallel runs of wire can be beneficial, but like everything else in this hobby, YMMV.

Agreed T. Another example; if the system were a shade thin/lean, I would try one large gauge wire. This would provide a touch of inductive reactance to lower the signal as it rose in frequency, thus tending to negate the thinness/leanness. It would also allow for maximum bass and lower midrange, adding a little more flesh to the voices.

I know it is kind of a tone control, but with no adjustments on a system, it could be helpful.

Cheers
Steve
This is an awesome post.
An array is on my bucket list, but it won't be happening anytime soon.
Some day, I'll think back to this thread, this post, and won't be able to recall what you said.  :duh
Title: Re: Line Arrays
Post by: Tinnitus Towers on May 14, 2017, 04:55:24 PM
I have recently been testing the effects of wire gauge on "sound" of my test speakers. But it has not been one solid wire, but multiple wires of 18 gauge in parallel.

Steve,

Do you have any measurement results that you could share that could help us quantify the increase in quality that you are seeing with your addition of paralleling 18 AWG wires? Not sure of the magnitude in distortion/frequency changes in your findings.

Basically, wanting to know if it's worth re-wiring 46 drivers in my arrays...

Thanks!
Title: Re: Line Arrays
Post by: steve on May 15, 2017, 07:54:31 PM
I have recently been testing the effects of wire gauge on "sound" of my test speakers. But it has not been one solid wire, but multiple wires of 18 gauge in parallel.

Steve,

Do you have any measurement results that you could share that could help us quantify the increase in quality that you are seeing with your addition of paralleling 18 AWG wires? Not sure of the magnitude in distortion/frequency changes in your findings.

Basically, wanting to know if it's worth re-wiring 46 drivers in my arrays...

Thanks!

The only thing I can do is to give some examples of the inductive reactance. I don't have any meters etc that will work with any accuracy.

1 length of 18 gauge solid straight wire, 6 feet long, at 20khz, has an inductive reactance of approximately 0,368 ohms.

1 length of 14 gauge solid straight wire, 6 feet long, at 20khz, has an inductive reactance of approx. 0,3472 ohms.

1 length of 8 gauge solid straight wire, 6 feet long, at 20khz,
has an inductive reactance of approx. 0,3155 ohms.

Notice not much difference when enlarging a single wire. Add one more wire, for two total wires, and reactance approximately halves. Three and 1/3 the inductive reactance. Change length to 1 foot, and inductive reactance is 1/6th. Halve the frequency, the inductive reactance is half.

I have not altered the wiring in my test speakers, approx. 3 feet, as my speakers seem to be very very nice. So it may or may not be worth it in yours. How long is the internal wiring of your speakers? Might try testing with other, simpler but excellent  speakers.

Cheers
Steve
Title: Re: Line Arrays
Post by: richidoo on May 16, 2017, 06:03:00 AM
Does cable geometry (twisting conductors) affect inductive reactance?

What affect does inductive reactance have on signal passing through the cable?
Title: Re: Line Arrays
Post by: steve on May 16, 2017, 05:59:10 PM
Does cable geometry (twisting conductors) affect inductive reactance?

Yes, it will be lower but not zero because the centers of the conductors would have to occupy exactly the same space. Typically, the inductive reactance will be reduced. It depends upon how close the wires are physically.

The closer the wires to each other, the higher the capacitance. The twisted speaker cable is much larger than having the +/- wires separated. If global negative feedback is involved, the feedback signal will be phase shifted, distortion will rise as the frequency rises. How much is dependent upon the amp design. Could be very little, or somewhat.

Quote
What affect does inductive reactance have on signal passing through the cable?

Think of a voltage divider. The higher the inductive reactance of the speaker cable, the lower the signal voltage is to the speaker driver. Of course, phase relationships are also involved.

One thing in our favor is that usually the driver impedance rises along with the speaker cable inductance. Still from my testing, the results are noticeable.

I just reduced my parallel speaker cables from 10 parallel 18 gauge wires to 8 parallel 18 gauge wires. There was a difference.
From a DC resistance stand point, the gauge was reduced from approximately 8 total gauge to 9 total gauge.

From my above post, inductive reatance....

1 length of 18 gauge solid straight wire, 6 feet long, at 20khz, has an inductive reactance of approximately 0,368 ohms.

1 length of 14 gauge solid straight wire, 6 feet long, at 20khz, has an inductive reactance of approx. 0,3472 ohms.

1 length of 8 gauge solid straight wire, 6 feet long, at 20khz,
has an inductive reactance of approx. 0,3155 ohms.

8 parallel speaker wires, inductance is only 0,046 ohms inductive reactance at 20khz. It is more like a direct connection to the amplifier (assuming no xover). And very little, if any cable capacitance if the +/- wires are separated.

Cheers
Steve
Title: Re: Line Arrays
Post by: richidoo on May 17, 2017, 07:24:26 AM
Thanks steve.
So in a feedback loop wewant short untwisted conductors.  Phase compensation with cap would not help because it rotates phase in same direction as the twisted conductor capacitance? Usually the ground leg is separated anyway.
Title: Re: Line Arrays
Post by: djdube525 on May 17, 2017, 08:44:15 AM
Does cable geometry (twisting conductors) affect inductive reactance?

What affect does inductive reactance have on signal passing through the cable?

FWIW... if ya want to geek out...

Here's a calculator for finding the inductance (L) of two parallel lines (https://www.eeweb.com/toolbox/parallel-wire-inductance) which can then be used to find the Reactance which is equal to 2*PI*f*L where f = frequency (more info here (http://www.electronics-tutorials.ws/inductor/ac-inductors.html)).



Title: Re: Line Arrays
Post by: steve on May 17, 2017, 09:41:27 AM
Thanks steve.
So in a feedback loop wewant short untwisted conductors.  Phase compensation with cap would not help because it rotates phase in same direction as the twisted conductor capacitance? Usually the ground leg is separated anyway.

It might sound good Rich, but no, you want only the capacitance that was originally designed in the feedback loop. Too much or too little will negatively affect phasing of the feedback signal.

But on speaker wires, I always keep the capacitance minimal.

525, yes, in general, paralleling inductors is similar to paralleling resistors.

Cheers
Steve
Title: Re: Line Arrays
Post by: richidoo on May 17, 2017, 11:40:12 AM
Thanks Dave

steve, when you parallel 8 conductors in SC, how do you separate them mechanically to avoid capacitance.
Title: Re: Line Arrays
Post by: steve on May 17, 2017, 02:01:58 PM
Thanks Dave

steve, when you parallel 8 conductors in SC, how do you separate them mechanically to avoid capacitance.

In my test setup, I just purchased either regular 18 gauge wire and cut to length. I have also purchased pairs of 18 gauge wire in common jacket and cut to length. Parallel the pairs together.
Do Not connect one wire to + and the other wire of the pair to -.

I just laid all the + 8 wires together and a foot or so apart from the - wires. Capacitance will be minimal, near zero. If all the + wires are close together, not a huge deal. Same for all the - wires. The main point is to separate the + from the - speaker wires.

Cheers
Steve
Title: Re: Line Arrays
Post by: richidoo on May 17, 2017, 06:10:36 PM
Right... no capacitance between the positives. Cool
Title: Re: Line Arrays
Post by: steve on June 16, 2017, 07:16:16 AM
I was wondering how your project is progressing Rich? Is there anything unexpected that you have encountered that we could benefit from knowing?

Cheers
Steve
Title: Re: Line Arrays
Post by: richidoo on July 10, 2017, 07:44:14 PM
Started working on this again. This is a big step of gluing the driver mounting nuts to the inside of the cabinet. Once the box is glued together, these nuts will not be accessible, so the gluing has to be in the right place and very strong so they don't pop off. Today I screwed all the drivers to the baffles in preparation for gluing the nuts to the inside of the baffles tomorrow. I will be gluing them with Loctite PL Construction urethane adhesive. It cures by reacting with moisture in the air, or water applied to bonded surfaces, and foams slightly. Very strong!!! I will just apply it around the edges of top of the nuts, nut under each nut, because I don't want to glue the mounting screws into the T-nuts.

6-32 x 1/2" button head hex screws and T-nuts.

Attached Pictures:
1. 16 drivers unpacked
2. Ready to assemble a strip of 16 drivers = half a speaker
3. 1 baffle assembled.
4. 4 baffles assembled, ready for T-nut glue
5. Closeup of driver assy
6. 64 drivers vs 4 drivers - which will win?
7. My daughter baked my BD cake(s) I'm 13yo
Title: Re: Line Arrays
Post by: djdube525 on July 11, 2017, 04:00:02 AM
Attached Pictures:
6. 64 drivers vs 4 drivers - which will win?

This doesn't seem like a fair fight... Lord Vader appears to be using the force to defend the current setup...  :rofl:


Nice progress Rich!


Title: Re: Line Arrays
Post by: Nick B on July 11, 2017, 07:22:27 AM
Started working on this again. This is a big step of gluing the driver mounting nuts to the inside of the cabinet. Once the box is glued together, these nuts will not be accessible, so the gluing has to be in the right place and very strong so they don't pop off. Today I screwed all the drivers to the baffles in preparation for gluing the nuts to the inside of the baffles tomorrow. I will be gluing them with Loctite PL Construction urethane adhesive. It cures by reacting with moisture in the air, or water applied to bonded surfaces, and foams slightly. Very strong!!! I will just apply it around the edges of top of the nuts, nut under each nut, because I don't want to glue the mounting screws into the T-nuts.

6-32 x 1/2" button head hex screws and T-nuts.

Attached Pictures:
1. 16 drivers unpacked
2. Ready to assemble a strip of 16 drivers = half a speaker
3. 1 baffle assembled.
4. 4 baffles assembled, ready for T-nut glue
5. Closeup of driver assy
6. 64 drivers vs 4 drivers - which will win?
7. My daughter baked my BD cake(s) I'm 13yo

Hmmm....a picture of you when you were 17 and now you are 13?? Is there a pattern here??
Congrats!
Nick
Title: Re: Line Arrays
Post by: Bob in St. Louis on July 11, 2017, 05:23:12 PM
Nice cupcakes!  :thumb:
Title: Re: Line Arrays
Post by: richidoo on July 11, 2017, 07:23:57 PM
Thanks! They were yummy!

I got the T-nuts glued on today. That PL adhesive is really something.
Start building the cabinets tomorrow.
Title: Re: Line Arrays
Post by: steve on August 03, 2017, 08:22:12 AM
Thanks! They were yummy!

I got the T-nuts glued on today. That PL adhesive is really something.
Start building the cabinets tomorrow.

3 weeks later, and the suspense is continuing to build.  :drool:

Cheers

Steve
Title: Re: Line Arrays
Post by: richidoo on August 03, 2017, 12:07:49 PM
Aha! Thanks for another wake up call Steve! I wouldn't make any progress without you!

You're intuition must be itchy cuz I'm actually already working on it today. I'm regluing the T nuts with CA glue because the PL construction adhesive that I used before is very strong and tough, but it doesn't wick under the TNuts to make a good enough joint. It's more like taping them on from above. I could only glue one side of the TNuts with PL while the drivers screwed down to hold the nuts in place, so some of the TNuts could rock a little on the other, loose side. The CA seeps under and glues it tight. I'm using Bob Smith medium viscosity 15 second cure, but on the rough side of the masonite it cures very slowly, but it's solid after 10 minutes. Luckily I haven't glued any fingers together yet, but there's still one baffle left. I like the first wiff of CA, reminds me of happy days in my previous stress free hobby of model airplane building. But after a few minutes the smell gets old fast.

Also today I will drill 4 small holes in each of the 64 divider panels that go between each driver, holes to allow the hookup wires to pass through. Some of the panels need less holes, according to the wiring schematic, but the most holes any panel needs is 4, so I'm drilling 4 in all of them, then I'll fill the unused holes after the hookup is done. That's easier than gluing each divider panel in a "correct" position, and messing it up. Also allows changing the wiring schematic if I already messed that up but don't know it yet. :)  Since all the drivers move the same, in same volume chambers, there shouldn't be any air movement through the holes, but I'll seal them up anyway, and the wires through the holes. Once the holes are drilled I can start the sexy job of gluing up the boxes.

Edit: My wife wants me to finish these so she can hear what all this work is for. So I am motivated to show it off for my biggest fan and that should accelerate my progress. Just don't hold your breath!  :roll:
Title: Re: Line Arrays
Post by: djdube525 on August 03, 2017, 01:36:13 PM
Edit: My wife wants me to finish these so she can hear what all this work is for. So I am motivated to show it off for my biggest fan and that should accelerate my progress. Just don't hold your breath!  :roll:

Ahh... the single biggest motivator of projects... the Mrs... 

not speaking from any recent experience... :rofl:
Title: Re: Line Arrays
Post by: Nick B on August 03, 2017, 02:46:55 PM
Aha! Thanks for another wake up call Steve! I wouldn't make any progress without you!

You're intuition must be itchy cuz I'm actually already working on it today. I'm regluing the T nuts with CA glue because the PL construction adhesive that I used before is very strong and tough, but it doesn't wick under the TNuts to make a good enough joint. It's more like taping them on from above. I could only glue one side of the TNuts with PL while the drivers screwed down to hold the nuts in place, so some of the TNuts could rock a little on the other, loose side. The CA seeps under and glues it tight. I'm using Bob Smith medium viscosity 15 second cure, but on the rough side of the masonite it cures very slowly, but it's solid after 10 minutes. Luckily I haven't glued any fingers together yet, but there's still one baffle left. I like the first wiff of CA, reminds me of happy days in my previous stress free hobby of model airplane building. But after a few minutes the smell gets old fast.

Also today I will drill 4 small holes in each of the 64 divider panels that go between each driver, holes to allow the hookup wires to pass through. Some of the panels need less holes, according to the wiring schematic, but the most holes any panel needs is 4, so I'm drilling 4 in all of them, then I'll fill the unused holes after the hookup is done. That's easier than gluing each divider panel in a "correct" position, and messing it up. Also allows changing the wiring schematic if I already messed that up but don't know it yet. :)  Since all the drivers move the same, in same volume chambers, there shouldn't be any air movement through the holes, but I'll seal them up anyway, and the wires through the holes. Once the holes are drilled I can start the sexy job of gluing up the boxes.

Edit: My wife wants me to finish these so she can hear what all this work is for. So I am motivated to show it off for my biggest fan and that should accelerate my progress. Just don't hold your breath!  :roll:

This is a great example of what I'm trying to preach! Men, stand up for yourselves! You are the king of the ...what?? I'm busy right now!! I can't...really, I don't want to... sorry. Have to go, the wife is calling...  :roll: :roll:
Title: Re: Line Arrays
Post by: tmazz on August 03, 2017, 05:12:38 PM
You're lucky Rich, most wives would be saying "You really don't think you're going to bring those monstrosities into the house, do you?"  :rofl:

Oh come on, we've all been there at one point or another...... :roll:
Title: Re: Line Arrays
Post by: BobM on August 04, 2017, 09:53:39 AM
Keep plugging Rich. There's a lot of construction to a line array.
Title: Re: Line Arrays
Post by: richidoo on August 04, 2017, 11:02:35 AM
Keep plugging Rich. There's a lot of construction to a line array.

Thanks Bob, you're right about that.
Glad you're watching. :)
Title: Re: Line Arrays
Post by: steve on August 08, 2017, 10:21:53 AM
Aha! Thanks for another wake up call Steve! I wouldn't make any progress without you!

I hope I am not a pest, love a great experiment/work.

Quote
You're intuition must be itchy cuz I'm actually already working on it today. I'm regluing the T nuts with CA glue because the PL construction adhesive that I used before is very strong and tough, but it doesn't wick under the TNuts to make a good enough joint. It's more like taping them on from above. I could only glue one side of the TNuts with PL while the drivers screwed down to hold the nuts in place, so some of the TNuts could rock a little on the other, loose side. The CA seeps under and glues it tight. I'm using Bob Smith medium viscosity 15 second cure, but on the rough side of the masonite it cures very slowly, but it's solid after 10 minutes. Luckily I haven't glued any fingers together yet, but there's still one baffle left. I like the first wiff of CA, reminds me of happy days in my previous stress free hobby of model airplane building. But after a few minutes the smell gets old fast.

Also today I will drill 4 small holes in each of the 64 divider panels that go between each driver, holes to allow the hookup wires to pass through. Some of the panels need less holes, according to the wiring schematic, but the most holes any panel needs is 4, so I'm drilling 4 in all of them, then I'll fill the unused holes after the hookup is done. That's easier than gluing each divider panel in a "correct" position, and messing it up. Also allows changing the wiring schematic if I already messed that up but don't know it yet. :)  Since all the drivers move the same, in same volume chambers, there shouldn't be any air movement through the holes, but I'll seal them up anyway, and the wires through the holes. Once the holes are drilled I can start the sexy job of gluing up the boxes.

Edit: My wife wants me to finish these so she can hear what all this work is for. So I am motivated to show it off for my biggest fan and that should accelerate my progress. Just don't hold your breath!  :roll:

That is one phase I don't like thinking about, making sure the nuts stay in place. I have not had any experience to see how long CA will work with wood. Will you need a combo of CA and CL to prevent nuts from falling after decades would work or just CA alone?? Using any washers, on either side??

Cheers and keep up the good work Rich.

Steve
Title: Re: Line Arrays
Post by: Nick B on August 08, 2017, 10:31:27 AM
rich, this is wery cool.  looking forward to hearing about the outcome.

eight years ago, i purchased 40 of these, and now that i am back in a house w/a big room, i may actually try to put together a line array myself:

https://www.parts-express.com/peerless-india-lko-120wff-5-1-4-fullrange-driver--299-280

i was thinking 15 or 16 per side, w/a few left over for spares.  at rated 45hz-18khz, with dsp, these could be made to run pretty-much full range at high efficiency.  as my woodworking skills are mediocre at best, i was considering simply mounting them in a baffle, and modifying a sonotube to accept the baffle. 

keep up the good work!   :thumb:

doug s.

Doug,
If you do it, you have to keep us posted on your progress, ok? I've seen line arrays a couple of times. I think years ago Audioquest produced one, or at least a guy who worked for them. It wasn't a completed speaker, so I never got to hear the final version
Nick
Title: Re: Line Arrays
Post by: richidoo on August 08, 2017, 11:12:24 AM
Quote
That is one phase I don't like thinking about, making sure the nuts stay in place. I have not had any experience to see how long CA will work with wood. Will you need a combo of CA and CL to prevent nuts from falling after decades would work or just CA alone?? Using any washers, on either side??

dougie and steve, thanks for the encouragement

CA glue is very strong, good bond to wood/metal. I think it will last. Masonite is acidic apparently, so it slows the cure of CA, but it's easily kicked off with some baking soda, or spit (if you're saliva is alkaline = young.)

It's not hard to glue on a new Tnut if one falls off, just have to get it lined up first, held in place by tape, then CA it with access through the driver opening. But better to get most of them glued on the easy way.  8)

I built these arrays of 3/16" masonite as a cheap trial just to hear what it sounds like, whether the concept deserves further development. If it sounds as good as claimed I might build it again in aluminum with rear mounted drivers.
Title: Re: Line Arrays
Post by: richidoo on August 08, 2017, 11:30:15 AM
https://www.parts-express.com/peerless-india-lko-120wff-5-1-4-fullrange-driver--299-280

i was thinking 15 or 16 per side, w/a few left over for spares.  at rated 45hz-18khz, with dsp, these could be made to run pretty-much full range at high efficiency.  as my woodworking skills are mediocre at best, i was considering simply mounting them in a baffle, and modifying a sonotube to accept the baffle. 

Great idea! With 20W power handling each you can EQ the bass to ur heart's content.
I thought about using preformed tubes for the cabinet like PVC pipe or sonotube. As sealed box, and high power handling, and intending to EQ anyway, the box volume isn't so critical.
Title: Re: Line Arrays
Post by: dBe on August 13, 2017, 03:15:23 PM
Aha! Thanks for another wake up call Steve! I wouldn't make any progress without you!

I hope I am not a pest, love a great experiment/work.

Quote
You're intuition must be itchy cuz I'm actually already working on it today. I'm regluing the T nuts with CA glue because the PL construction adhesive that I used before is very strong and tough, but it doesn't wick under the TNuts to make a good enough joint. It's more like taping them on from above. I could only glue one side of the TNuts with PL while the drivers screwed down to hold the nuts in place, so some of the TNuts could rock a little on the other, loose side. The CA seeps under and glues it tight. I'm using Bob Smith medium viscosity 15 second cure, but on the rough side of the masonite it cures very slowly, but it's solid after 10 minutes. Luckily I haven't glued any fingers together yet, but there's still one baffle left. I like the first wiff of CA, reminds me of happy days in my previous stress free hobby of model airplane building. But after a few minutes the smell gets old fast.

Also today I will drill 4 small holes in each of the 64 divider panels that go between each driver, holes to allow the hookup wires to pass through. Some of the panels need less holes, according to the wiring schematic, but the most holes any panel needs is 4, so I'm drilling 4 in all of them, then I'll fill the unused holes after the hookup is done. That's easier than gluing each divider panel in a "correct" position, and messing it up. Also allows changing the wiring schematic if I already messed that up but don't know it yet. :)  Since all the drivers move the same, in same volume chambers, there shouldn't be any air movement through the holes, but I'll seal them up anyway, and the wires through the holes. Once the holes are drilled I can start the sexy job of gluing up the boxes.

Edit: My wife wants me to finish these so she can hear what all this work is for. So I am motivated to show it off for my biggest fan and that should accelerate my progress. Just don't hold your breath!  :roll:

That is one phase I don't like thinking about, making sure the nuts stay in place. I have not had any experience to see how long CA will work with wood. Will you need a combo of CA and CL to prevent nuts from falling after decades would work or just CA alone?? Using any washers, on either side??

Cheers and keep up the good work Rich.

Steve
I have used CA since the 80s and never had a failure even after repeated speaker R&R.  I always use Baltic birch as one of the front baffle layers to get a final baffle thickness of at lease 1".  Considerably thicker baffles for larger drivers.  Normally I'll use 1/4" -1/2"MDF, Medex or tempered Masonite for the external layer just to make it easier to finish.

ALWAYS use machine screws at least as long as the baffle thickness and use a lock washer under the screw head on drivers bigger than 7 inches.

Small drivers I drill the screw holes 1 size under the tap drill size for the screw being used.  Run a tap through the hole.  The tap will it and compress the BB fibers which increases the fiber density.  Apply Scotch tape to one side of the hole and fill the hole with thin CA and let it penetrate the wood for a couple of minutes.  Which the CA out with a pipe cleaner and let it cure naturally for 30 minutes.  Remove the cello tape and then spray CA accelerator in the hole and wait 5 minutes.  Then re-tap the hole.  I use this method on drivers up to 8".  Like I said - no failures. 

Larger drivers I normall use threaded inserts, but these need to be installed before routing the driver holes.  Drill the smaller hole first, then counter bore for the threaded insert.  Install the threaded insert and then run the tap through from the insert side.  Here is where disaster can happen.  Here is where disaster an happen. Stand the baffle board on one side and slowly, carefully saturate the wood (MDF, whatever) with thinCA.  Some fill flow underneath the insert.  Let it cure and then re-tap one more time.

Bullet-proof.

Sounds like a lot of work, but after you do it a few times it is faster than one would think and is way quicker than having to fix a bad hole.
Title: Re: Line Arrays
Post by: richidoo on August 13, 2017, 03:49:31 PM
I LUV John Inlow. Great site! I check it out often, and planning to build some of his horns. But I hadn't noticed that line array build technique. Very clever! Drivers' center to center distance needs to be as small as possible to keep lobing confined to the highest freqs. The farther drivers are from each other the farther away you must sit to not notice the lobing when standing and sitting.

PI Good idea about threading BB. Thin CA works good to make any wood into a strong "composite." FYI You can make your own CA accelerator from water saturated with baking soda.

I didn't think about preventing driver screws from backing out from vibration, so I'll have to use loctite red if necessary. Or move on to the aluminum baffle version sooner if it's a problem.
Title: Re: Line Arrays
Post by: richidoo on August 15, 2017, 03:05:49 PM
Finally gluing up the boxes. Slow going but feels good to be making progress.
Title: Re: Line Arrays
Post by: richidoo on August 29, 2017, 05:39:20 PM
Gettin rollin on these now.

1, 2. Gluing on the other back panel
3, 4. Install wiring
5. Test fitting the front baffle
6, 7. Gluing on the front baffle
8. Ready for the final 2 side panels

The side panels have a 45 chamfer cut on a table saw. They are 53 inches long and for some reason the chamfered edge is not straight. So when it fits up under the front baffle overhang it leaves a gap. All 8 side pieces are the same way. Tomorrow I will try to recut them, as there is enough extra meat to recut that edge, but I'm not sure why it happened. Will have to make extra careful saw setup.
Title: Re: Line Arrays
Post by: tmazz on September 01, 2017, 08:28:00 PM
Wait a minute!!!!!!

Your wife is letting you glue together speaker cabinets on her kitchen counters???????    :shock: :shock: :shock:

That woman must be a saint.  [-o<
Title: Re: Line Arrays
Post by: richidoo on September 01, 2017, 09:47:19 PM
Yes, she certainly is!

My daughter's baking messes are much worse. At least my glue is sterile.  :-P
Title: Re: Line Arrays
Post by: BobM on September 02, 2017, 07:06:20 AM
Are you going to take over the living room with these monsters or have you moved upstairs yet?
Title: Re: Line Arrays
Post by: rollo on September 02, 2017, 09:21:03 AM
Looking good professor. Getting close.


charles
Title: Re: Line Arrays
Post by: richidoo on September 02, 2017, 12:42:28 PM
Are you going to take over the living room with these monsters or have you moved upstairs yet?

Probably staying downstairs in the family room as it was when you were here.

I built them for moving the stereo into the small downstairs music room, but I think they will sound better in the big room and maybe they can go into the corners which be more WAF.


Looking good professor. Getting close.

Thanks Charlie
Title: Re: Line Arrays
Post by: steve on October 17, 2017, 07:32:24 PM
Gettin rollin on these now.

1, 2. Gluing on the other back panel
3, 4. Install wiring
5. Test fitting the front baffle
6, 7. Gluing on the front baffle
8. Ready for the final 2 side panels

The side panels have a 45 chamfer cut on a table saw. They are 53 inches long and for some reason the chamfered edge is not straight. So when it fits up under the front baffle overhang it leaves a gap. All 8 side pieces are the same way. Tomorrow I will try to recut them, as there is enough extra meat to recut that edge, but I'm not sure why it happened. Will have to make extra careful saw setup.

Looking mighty good Rich. Looks like you are getting pretty close to wiring and testing.

Keep up the good work.

Steve
Title: Re: Line Arrays
Post by: richidoo on October 17, 2017, 07:58:39 PM
Slow now, but 2 of 4 boxes are built and wired.
Title: Re: Line Arrays
Post by: steve on November 26, 2017, 09:58:21 PM
Slow now, but 2 of 4 boxes are built and wired.

I hate to sound naggy, but any more progress Rich? Just curious.

Steve
Title: Re: Line Arrays
Post by: richidoo on November 27, 2017, 06:27:38 PM
Thanks for the bump Steve!

The arrays are on ice for now. I have bigger fish to fry at the moment.

But I need to clean up my audio messes all over the house, so I will have to finish them soon.

Tapping on the undamped box makes the large internal panels ring with high Q. So I need to damp and brace those.
Title: Re: Line Arrays
Post by: steve on February 04, 2018, 04:33:35 PM
I was wondering if you have had any further time with your line array speakers Rich?

Cheers

Steve
Title: Re: Line Arrays
Post by: steve on July 25, 2018, 08:59:21 PM
I was wondering your line array speakers are coming along Rich?

Cheers

Steve
Title: Re: Line Arrays
Post by: richidoo on July 26, 2018, 05:51:49 AM
Hi Steve,
Not much done lately, except moving them around to keep them out of the way. :D  I got a set of Legacy Focus SE last fall, they have proved adequate for listening, so I haven't made any progress on the line arrays. But I have lately been thinking about working on them again.

I need to damp the hardboard to move forward, and 2/4 cabinets are fully built so I'll have to squeeze the damping sheets through the small driver holes. I would use self adhesive roofing membrane from GAF but it's not readily available in single rolls, and a pallet is 20 rolls and I don't really need that much. So I'll have to find something similar. There is patch material in 1 foot wide rolls, but it's thin so i might need couple layers, or both sides of the internal panels. Some progress is made however in that I now have a stereo amp with plenty of power for the line arrays. Thanks for the nudge, Steve. It's always appreciated!
Rich
Title: Re: Line Arrays
Post by: steve on July 29, 2018, 09:21:02 PM
Hi Steve,
Not much done lately, except moving them around to keep them out of the way. :D  I got a set of Legacy Focus SE last fall, they have proved adequate for listening, so I haven't made any progress on the line arrays. But I have lately been thinking about working on them again.

I need to damp the hardboard to move forward, and 2/4 cabinets are fully built so I'll have to squeeze the damping sheets through the small driver holes. I would use self adhesive roofing membrane from GAF but it's not readily available in single rolls, and a pallet is 20 rolls and I don't really need that much. So I'll have to find something similar. There is patch material in 1 foot wide rolls, but it's thin so i might need couple layers, or both sides of the internal panels. Some progress is made however in that I now have a stereo amp with plenty of power for the line arrays. Thanks for the nudge, Steve. It's always appreciated!
Rich

I can understand summer time is out and about, cookouts here etc. Pretty much finished with my two ways, but only an adjustable control tweak, not finishing the outsides as I would have to move them and it took so long to get them right. So the outside still looks like plywood.

However, soon will be fall and winter so got to make the most of summer time.

cheers and continued success Rich.

steve
Title: Re: Line Arrays
Post by: richidoo on July 30, 2018, 10:05:01 AM
I usually work on speakers during the summer and hibernate from it in the winter. So now would be a good time to work on them. I have the time, but not into it now especially with good, full range commercial speakers in the house. I can accept their flaws without taking it personally, or punishing myself with perfectionism, so it is altogether a more pleasant experience. No rush to get back into that frame of mind. But I will someday.
Title: Re: Line Arrays
Post by: steve on July 14, 2019, 09:16:57 PM
Rich,

Wondering the other day if you had a chance to do anymore work on your speakers?

Just curious.
steve