Author Topic: Line Arrays  (Read 28234 times)

Offline richidoo

  • Out Of My Speaker Cabinet
  • ******
  • Posts: 11144
Line Arrays
« 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!


Offline HAL

  • Audio Neurotic
  • *****
  • Posts: 1270
  • Audio Mad Scientist
    • Hollis Audio Labs
Re: Line Arrays
« Reply #1 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. 

Offline rollo

  • Industry Participant
  • *
  • Posts: 6982
  • Rollo Audio - Home demo the only way to know
Re: Line Arrays
« Reply #2 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
contact me  at rollo14@verizon.net or visit us on Facebook
Lamm Industries - Aqua Acoustic, Formula & La Scala DAC- INNUOS  - Rethm - Kuzma - QLN - Audio Hungary Qualiton - Fritz speakers -Gigawatt -Vinnie Rossi,TWL, Swiss Cables, Merason DAC.

Offline richidoo

  • Out Of My Speaker Cabinet
  • ******
  • Posts: 11144
Re: Line Arrays
« Reply #3 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.

Offline richidoo

  • Out Of My Speaker Cabinet
  • ******
  • Posts: 11144
Re: Line Arrays
« Reply #4 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...
« Last Edit: December 13, 2016, 09:41:41 AM by richidoo »

Offline BobM

  • Audio Neurotic
  • *****
  • Posts: 3318
Re: Line Arrays
« Reply #5 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.
Laugh and the world laughs with you. Cry and you'll have to blow your nose.

Offline richidoo

  • Out Of My Speaker Cabinet
  • ******
  • Posts: 11144
Re: Line Arrays
« Reply #6 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.

Offline Nick B

  • Audio Neurotic
  • *****
  • Posts: 4093
Re: Line Arrays
« Reply #7 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!




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
Orchard Starkrimson Ultra amp
Supratek Chardonnay preamp
JMR Voce Grande speakers
Border Patrol SEi dac
Holo Red streamer
Hapa Aero digital coax
WyWires Silver cables
TWL Digital American II p cord
Audio Envy p cords
Roon, Tidal, Qobuz
PI Audio UberBUSS

Offline richidoo

  • Out Of My Speaker Cabinet
  • ******
  • Posts: 11144
Re: Line Arrays
« Reply #8 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!

Offline richidoo

  • Out Of My Speaker Cabinet
  • ******
  • Posts: 11144
Re: Line Arrays
« Reply #9 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.

Offline mresseguie

  • Obsessively Audiophilic
  • ****
  • Posts: 491
Re: Line Arrays
« Reply #10 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.




« Last Edit: December 31, 2016, 05:06:04 AM by mresseguie »
Daedalus Audio Apollos; Fritz Loudspeakers LS/5-R
SW1X NOS DAC III BAL/SPL; Holo Spring3 KTE
Don Sachs Model 2 preamp
Don Sachs dual mono 300b; Nuprime Evolution STA
Hapa loom
PI Audio UberBUSS, DigiBUSS, Uber-MiniBUS

Offline richidoo

  • Out Of My Speaker Cabinet
  • ******
  • Posts: 11144
Re: Line Arrays
« Reply #11 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 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.

Offline Bob in St. Louis

  • Audio Neurotic
  • *****
  • Posts: 1273
Re: Line Arrays
« Reply #12 on: January 01, 2017, 02:44:09 PM »
Looking forward to seeing some pics of this one.
Sounds pretty cool Rich!

Offline steve

  • Audiologist
  • *
  • Posts: 1238
Re: Line Arrays
« Reply #13 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

 
Steve Sammet (Owner, Electron Eng, SAS Audio Labs, Ret)
SAS "V" 39pf/m 6N copper ICs,
SAS Test Phono Stage
Acutex 320 STR Mov Iron Cart
SAS 11A Perfect Tube Preamp
SAS 25 W Ref Triode/UL Monoblocks
2 way Floor Standing Test Speakers

Offline richidoo

  • Out Of My Speaker Cabinet
  • ******
  • Posts: 11144
Re: Line Arrays
« Reply #14 on: January 01, 2017, 09:34:01 PM »
Thanks for the encouragement fellas. I will post some pics.