AudioNervosa
Systemic Development => Psycho-Acoustics => Topic started by: richidoo on July 27, 2007, 02:20:52 PM
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I have noticed recently that upgrades on the system seem to increase the contrast between direct and reflected sound. The better the direct sound gets, the more it is smeared when interacting with the room sound which is consistently poor. At low volumes the room sound is not as much of a problem although the room reverb colors the ambience of the recording, sometimes in a good way. At higher volumes, the room intrudes much more, I wonder if there is some exponential function involved. But the net result is negative for upgrades to the system. I guess if I could get the system to sound as bad as the room, I would be satisfied? haha That would be hard.
I have been searching for acoustic treatments with the acreage of coverage I need and still have WAF. Panels are not acceptable no matter what they are covered with. Some online estimator suggested I need about ~50 2 x 4 panels. Covered in purple, no doubt. But my wife recently suggested thick velvet drapes, so that was encouraging. If she'll go for something as tacky as that, maybe something a little more chic and more effective would fly. I asked her what she thought about fabric covered walls today, and I was surprised when her response was "I wanna see the fabrics" instead of some crack about living in an office cube.
So to do a little proof of concept before I get too excited, or before I spend any more money on this godforsaken hobby, I laid out some quilts. 4 on the floor and table top in the kitchen area behind listening area, and one on the wood floor and one hanging on a door on the side of the listening area. Altogether it was about 600-700 sf of poor quality absorption. Clap test felt like a good improvement, and immediately the whole room got cozier.
Listening to music it was a big improvement. I could hear things that were obscured before, and finally at long last that annoying cold evil soul shivering echo that is mixed in with every sound was cut way back. I was happy to hear that sound in my own house.
Hopefully covering up some walls and some ceiling with real absorption material will solve this shout problem at last. I have to admit it was a fun listening session with the quilts strewn around everywhere! I'll try to post more on the project here as it goes.
Rich
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Rich,
Good luck with the new line of pursuit! Hopefully, you will find at least a partial solution to your sonic woes. I know that you've been trying hard, but I still think your system/room has always sounded good, every time I've been over there.
Of course, I just may have 'crap' for ears and can't hear what has been driving you crazy. Who knows...maybe my system/room is sonically challenged. However, I seem to just be able to sit back and enjoy the music...without picking it apart.
SEE...being simple-minded can come in handy after all :rofl:!!!
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Rich, I'm interested in your experiment(s)....look forward to any progress..
WEEZ
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Wow, congratulation! :) I know it's tough to get these things worked out...
I've often thought about padded walls for a number of reasons. ;)
If you go to Southpoint Mall, there's a store called "Metropolitan Deluxe" in the outside area that has a large padded wall that was very close to something I'd do.... and may still do in the new room. I thought it looked very 'chic'... ;)
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simple minded... yeah, right!.... A real country dumpling! :rofl: It sounds good when you're here because it's mostly your electronics playing! hehe
Well, Steve, you know the latest upgrade that made the room really sound like CRAP was speaker wire. Yup, I had to do it, I'm just wired that way, can't resist the temptation. I see the fruit just hanging there and I reach out for it, and..... DAMN I did it again! You're really gonna hate me when I send you home with it. :lol: I will only say one thing for fear of corrupting other unsuspecting innocent lambs: "Art Dudley is right!" ... and not another word! :-$
(http://jpslabs.com/super_3_sp.jpg)
The local RPG dealer has some BAD panels for me to take home to try. The first hit is free, right? I don't even wanna go there, but the pull is just too great to resist. I know I'm gonna regret this one. They are a "little pricey" as is all RPG stuff. I wanna try to keep it simple and low buck. Thanks for the encouragement WEEZ and Carl, I'm psyched to get started.
Julie was joking about putting up padded fake leather with the buttons like an overstuffed smoking chair, or a wall in 1940s jazz club. I told her leather is terrible acoustics. She said I need to lighten up. hehe
Rich
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I must need coffee... can't understand your post, there Rich. ;)
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Yeah that is a little far out. :shock: Late night, low S/N. Naptime today.
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Richadoo,
Do you know how to idendtify your first and second reflection points?
Do you have a dead or live front wall? Do you have a dead clg. and live floor?
If not the floor and clg. should be opposite as well as the front and rear walls. Check with your speaker manf. to find out want your speaker perfers. Say a live front wall, then the rear wall should be deadened.
With reflection points, you will need a partner to help. you will need a flashlight and mirror. First identify the center of your listening position. Then while aiming the flashlight from the top of your speaker[ centerline ] to the side wall [ right speaker, right wall], place the mirror on said wall and move along wall until the light shines at the center of your chair. Then repeat process with left speaker. Now to get second reflection point, start with left speaker flashlight atop and aim at right wall. repeat for right speaker. You can use same method for clg. and floor as well. Once you determine the reflection points then you can get Wifey involved to select a material or the like to coincide with your decor.
I use shades and blinds [ wood or plastic ] to accomplish absorbing and reflecting or absorbing where needed. You will be amazed when you open and close blinds to varying degrees as the soudstage changes with the adjustments. Bass now is a different story altogether. Digital equalization is best suited for this, IMO. Bass traps are effective but ugly and expensive. I would recommend a Berhinger for this purpose. It is especially suited for Bass, I never cared for the full Monty as the sound was thin and bright. Not so with the Bass however, it is awesome. Another great tweak for subs is raising them 22% of your clg. hght. off the floor. This is an ASC tweak and is very, very affective. So multiply your room hght. by 22% and your in business. ASC makes a sub trap for this purpose but again it is not cost effective. Do your room right and you might stop trying IC's and cables as tone controls as it has its limitations IMO.
hope this helps.
rollo
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Thanks rollo! I got a good smile from your sage advice. I have tried almost everything you suggested! 1st refections are not problem, because side walls are pretty far away, but 4 inch panels 4x4 feet made no diff on sides. Front wall is live, but I tried deadening it, didn't like that. Rear wall is far away. Ceiling is a possibility for 1st reflection trouble, but decorator strongly objects. I should still try it to rule it out, not sure to hang absorption on ceiling without cables and screw eyes :? But treatments have helped make bass within 12dB down to 20hz, -5 at 16Hz :) My main problem is midrange echo length due to large room with all hard surfaces. Should be easy to fix and quilts on floor proved this to some degree. But getting decorator approval has been the challenge. Covering the whole ceiling in white panels with thin lines doesn't seem like a big deal to me, but it's a no go, category = clutter.
On the bright side, I have learned to heed Peter Walker's advice and turn it down! The room is not as excited at lower volumes, I don't know why. The speakers and amps are still plenty dynamic at low levels and bass is fine down low too. I listen as softly as I can, and just imagine I am in my real life nosebleed seats at the symphony concert. This strategy works best at night when background noise is minimal. I shut off the fridge and it is almost silent. Remembering to turn on the fridge when tired after late night listening is the new challenge. My eye bags are not improving from the late nights.
Still working on possible wall treatments for the mids but it is a journey. She loves tapestries but not a lot of open wallspace to put them.
Thanks rollo!!
Rich
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I had some fun doing an acoustic experiment today. I made a pseudo anechoic chamber on my kitchen table out of FG acoustic panels piled into a box all around me. (Thanks to Carlman for loaning me the panels.) Interior volume was 32 cu feet, so definitely closed field situation, even with the hole in the bottom for the body to poke up through the table. I put cheap speakers inside, and stuck my head up through a hole made by removing a table leaf. It was very interesting. Detail retrieval even with the Infinity Entra 1 was awesome. Tape hiss otherwise unnoticeable became unbearable because it was was hiding details I would otherwise hear clearly. I started with my old Technics 40wpc stereo receiver and Nomad mp3 player, but that sounded very edgy and distorted with the details so well revealed, so I switched to wireless SB and Cary SLI-80, still with home depot stranded speaker wire. Big improvement in smoothness, but lows and highs still too loud. The mid range tone was superb but the tweeters really sounded forward and harsh. Bass at first was overwhelmingly loud, unlistenable. These are only 5" woofers, but they played down to 40Hz (and dead silent below that using test tones). 60-120Hz was way too loud (+20dB) due to the closed field acoustic, which was part of what I wanted to hear for myself after reading about it in Loudspeaker cookbook. Ported speakers just weren't intended for this situation and they suffered with screwy EQ, hi and lo.
The feeling of stuffy anechoic was weird at first, but after 30 minutes in there I was quite comfortable with it, it is really just the unfamiliar silence that "feels" stuffy. Once the ears adjust to the new lower noise floor, the stuffy feeling is gone. We hear noise all the time, and the brain adjusts to it. So when you take it away, brain in homeostasis wonders: :wtf:
OHMYGOD the details!!!! I could hear the movement of piano foot pedals and the keyboard action, and the engineer coughing in the auditorium a long distance away. I could hear a lot more wood on Julia Fisher solo violin than on the big speakers. Lots of fuzz, rasp, wood, all that fart and puke sound effects that violins make live was revealed clear as day - on $150 speakers from Crutchfield. Granted, the Infinity CMMD mid drivers are superb, but still not really a high end speaker - or is it? Hmmm, in a well treated room, and the right situation, I think it is! Why have expensive speakers, to better deal with room anomolies. I know that my Legacys are designed around common room acoustic problems, compensation built right in. And it cost me too. ;)
My wife Julie climbed in there too, she thought it sounded great. But on highly produced pop music, it is too revealing of punches, mixing flaws, EQ changes, even digital phase processing for Madonna's magic acoustic tricks. Laid bare for all to hear, clear as day, and very distracting from the musical message. The digital processing tricks like phase sounded like static, or 32kbps mp3 hash. On the big stereo it sounds fine, can't hear it at all. Quite an eye opener. Do I wanna hear crap like that, well, I don't know. On good stereo recordings, I do wanna hear it because it lets me feel the rear wall of the stage, or the woody rosin of a violin. But on normal pop records, no thanks, it is unintended production noise, not music. I don't think I want my expensive high end system (including the bad room acoustics) to be glossing over so much detail though, when a <1000 rig shows all (not including kitchen table and coconut oil pail.) haha
Bass was WAY too big at first, with speakers deep in the "front" corners, and with the semi closed field. I opened it up to the outside by removing the "rear wall" panel and pulled the speakers away from the front wall by about a foot, moved them close together and put my head into a 18" triangle. Wow. Clarity, intensity, details, tone. Not as stuffy. Almost as good as Carl's new Piega's that I heard yesterday!
So I learned something, I liked the reflection free sound, I like details, I like being able to hear deep into a recording, even the flaws. A little more ring would be more comfortable and probably more enjoyable, but I wouldn't want to give up too much of that detail. A larger space would feel better and allow drivers to gel better with some distance. Some EQ would even out the bass and tame the highs even with these speakers which normally sound fine in a real room. Maybe single full range drivers would be interesting. I like not hearing the refrigerator running while I'm listening to music. I will keep on with this acoustics exploration, I have some more ideas to try. 8)
Thanks Bryan, for being so consistent in nudging me out of the big ring. I used to think I liked it, because when I deadened the front wall it contrasted too much with the rest of the super live room so it didn't sound good, even though it was solving specific imaging problems. When the whole "room" is controlled, it sounds awesome. The real acoustic is recorded on the CD, I don't need more from the room. There's no way I can deaden enough of my big room to tighten it up, Julie says forget it and my neighbor, our talented and free decorator, has chosen sides too. My mental gears are spinning. Next experiment will need lumber. :shock:
Pictures! (http://parkwestlake.com/nopw/rich/anechoic/index.htm) (this is funny...)
Rich
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:rofl:
Rich, those pictures ARE funny :lol:
WEEZ
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I'm liking the pics!
Just remember that the bottom end in an experiment like that is still totally dependent on the room you're in - not your little chamber. The bass will go right through to a large extent and still be modally influenced.
You really wouldn't want the whole room that kind of dead. The idea is to have a MODERATE amount of absorbtion/diffusion spread throughout the space. You have experienced the issues when you only do 1 area - it seems out of place to the rest.
As an experiment try:
- 1 panel straddling each corner
- 1 panel behind each speaker
- 1 panel between the speakers
- 2 panels on each side wall (humor me here I know they're far away)
- 2 panels on the rear wall behind your seating position
- Rug on the floor between you and the speakers.
This is a relatively unobtrusive setup in comparison to the large room and the panels (depending on what they are) could be covered in a fabric that's more WAF and free designer friendly.
Bryan
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You have experienced the issues when you only do 1 area - it seems out of place to the rest.
Yup, that's it.
While I can't keep them there permanently (rear wall is stove/countertop) I can definitely setup your suggested arrangement far easier than tabletop chamber :lol:. I'll give it a try Bry, thanks...
Rich
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Congrats Rich, you just invented - ummm...headphones!
Seriously, I'm not suprised that you are hearing all sorts of details now - you are listening in the "true" nearfield. Assuming you did the same thing in a room, many of those details would be lost due to distance attenuation. I'm suprised that the freq response is linear. I would expect a brighter response will little bass.
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Yeah, there was a brighter response, but the small volume of the space makes the bass louder too.
I've heard the headphone observation before and I resemble that remark! Actually it was because of a set of ear buds that got me thinking about trying this! Thanks Bob!
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Rich....
From those photo's....you got a bad case of nervosa..... :rofl:
But thats how you learn things.... 8)
Carl....What was the acoustic setup that Bruno use to use ?
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LW, I was thinking the same thing... this reminds me a LOT of Bruno's 'foam cocoon'... I'll try to find a link or photos when I get a chance... I think Bruno would even enjoy the photos and appreciate the experiment.
Rich's findings are not unlike my own... and I've found there's no such thing as too much absorption... (however too much in one part of a frequency range isn't good). I like the anechoic-ish sound... and you can do it nearfield... but when you get it into a bigger room, you have to balance room effects with absorption... and how much room coloration you like... which, btw, deteriorates the details, in my opinion... ;)
Really glad you tried this experiment... :)
-C
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Rich,
Really well done man. I thought I have seen it all.
rollo
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Rich.
I owe you. My wife was shoulder watching and saw your pics of you in the iso area. I've now dropped farther on the relative nervosa scale in her mind...
Bryan
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Thanks, glad I could be of service. :D Wait til you see the next experiment.
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As an experiment try:
- 1 panel straddling each corner
- 1 panel behind each speaker
- 1 panel between the speakers
- 2 panels on each side wall (humor me here I know they're far away)
- 2 panels on the rear wall behind your seating position
- Rug on the floor between you and the speakers.
I tried placing the panels as you suggest, but the room is so big I couldn't really hear much effect. Some of it I had tried before but not all at once. While I was at it, I noticed that with panels behind speakers and in the center of front wall, the soundstage was really weird and disjointed. It seemed like the reflective spaces between the absorbtion were refelcting strongly in two separate patches, which were then interfering, I dunno, but it was weird.
So I thought, if those untreated patches are sounding so weird, cover them up too! While I was at it I raised the behind the speaker panels up on top of tritraps for even more bass trapping. The result was great improvement, and my wife even said she likes the way it looks - :? Clarity, power and tone are improved. Bass is tight and "louder." Everything is louder, I have to turn down the volume by about 20% to get the same preception of power. But if I keep it up at the normal level the music is much more enjoyable at the higher perceived volume than without the treatment. High frequency forwardness is evident now maybe because I can hear it so much more clearly, and my system is tuned to overcome the smearing and distorted mids and highs. I can easily hear the crappy quality of the mixes on some albums, especially in the highs, while others still sound great, but more detailed. Shouting quality that I keep mentioning is noticeably diminished, at least coming from the front.
The ambience that was so delicious playing music at lower volumes without the front wall absorption is gone, but replaced by recorded ambience which is more appropriate. Priot to the change of course there was recorded ambience combined with my room's ambience. The room drowns out the recorded and is more natural sounding because my brain is adjusted to expect it both from listening habit and because of brain/space awareness. I'm in the room, so I hear the rooms shape easily. That is what I didn;t like about Tact, it changed the shape of the room artifically by manipulating the phase and timing so I would get a headache from being disoriented to the sound I was hearing. In everyoether way the tact's result was awesome. Most people are not as sensitive to such things as me. Carl is hyper sensitive and it never bothered him. Maybe the assymmetrical room shape exaggerates the tact effect.Whatever. With less room "ambience" I can hear more music details across the band, and feel the low mids more.
With the front tamed, echo from the sides and especially rear are very noticeable, but they are softer and farther away, so it is an overall improvement. The sound as it is now is pretty weird, so it is not a long term solution, but just an interesting experiment. It definitely demonstrates how much distortion from low bass to high freq treble was coming from the front wall reflection. SBIR affects more than just bass freqs, although bass was the most obvious imrpvement. Putting panels and tritraps directly behind speakers didn't have as big an effect as the whole wall, and it screwed up the ambience so it was pretty annoying.
The interesting thing is that in order to do this experiment I had to draw upon all the panals I have in the house, all of which were previously placed in corners along the floor and wall corners to trap bass. The light colored ones are Carl's. Placed in corners around the room they made a big difference compared to nothing, but when I removed them from the corners and placed them flat against the front wall, bass tightened and got louder by a large margin. Not what I was expecting, but I did not realize what a big effect the front wall was having in screwing up the direct sound. Speaker Boundary Interference Response is real and has a big effect! Pulling speakers away from front wall or absorbing front wall reflections reduces it.
This makes me wish even more for a fully treated room. I'll hang some quilts on the side walls tonight to try to tame them down a bit too.
There's a lot to this acoustic thing. I think I like a deader sound, the opposite of what I first thought. It allows me to hear much more detail and feel the music better. The recorded ambience is more enjoyable than the room sound. Maybe that's not as true with studio recordings which use fake ambience. There is so much crap on those that listening in too much detail reveals what poor recording quality is really there. A new Tori Amos CD sounded really rough, while a Bartok Concerto sounded much better.
Thanks for the great idea Bryan!
Rich
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(http://parkwestlake.com/nopw/rich/sbir.jpg)
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Absolutely. If you can do all that on the front, it's absolutely better. What I had laid out for you previously was to attempt to at least partially deal with all of the probable issues in the room. Now, if you can borrow a few more and leave the front wall covered AND do the side reflections and kill the nulls off the rear wall, I think you might begin to like this.
As a further experiment if you can keep the borrowed panels, try to live with it like this for a week or two and then take them away.
Bryan
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Thanks Bry. The rear wall is my kitchen, with cabinets countertop and stove, so I will never be able to do anything back there, except temporary, but it is 25 feet behind me, the only saving grace. It is not too bad except for the reverb decay time. I'll ask Carl for a few more panels while he is broken down for moving next week. I will be putting temporary quilts on the side walls and floors tomorrow. Looking to get some drapes and such too. Can a tapestry hang over an acoustic panel and still allow good absorbtion? Sometimes they are woven pretty tightly. But those will allow permanent placement of panels on the walls behind them. My wife loves tapestries.
The ceiling in the listening area is treatable, and I know you have mentioned that to me in the past. Have you any experience with those cotton acoustic panels, ala "echo eliminators?" Do you know if they are soft or hard like FG panels? They have a stretched fabric DIY system that looks pretty good. I guess you could put FG under it too, but they say the cotton absorbs as well. Working with FG gives me the creeps. I have can lights on that ceiling, so I will need to fabricate something custom to work around those.
As always, thanks for the advice.
Rich
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Too bad about the back wall. But, we do what we can do.
The tapestries will be trial and error. For the front wall, it'll likely be just fine as you're primarily interested in SBIR control anyway - but there will be some benefit from HF absorbtion based on bounce out of the kitchen and back to the front.
My business (not GIK) has access to the cotton products. Yes - they work very well. They'll outperform rigid FG inch for inch and pound for pound. They're a bit more expensive but also come in multiple colors. They are not as rigid as FG so a frame and/or some stronger method of attachemet (especially on a ceiling) is required. The track system is pretty nice too.
Bryan
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Very cool. BTW, Do you have a biz website Bryan?
Thanks
Rich
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Clickie my globe icon under my avatar.
Bryan
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:duh
VVVVVVVery nice. Thanks
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It still needs some work but things have just been crazy busy lately.
Bryan
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Any nicer and you would have "too much" biz. haha
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You certainly deserve the business. you have shown on this forum that the free advice you give has NO AGENDA. Your professtional advice even helped me out, thank you. keep up the good work and the best for your business.
Rich you scored here. Have fun.
rollo
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Lots of audiophile GIKkers buy from them because of Bryan's patience and helpful advice over the years. After a month of email tag with another company who sells this stuff but wouldn't give me straight answers unless I called on the phone which I could never remember to do, I almost fell out of my chair when I found it displayed plainly with prices on Bryans site. My plans for acoustic experiments are starting to get a little wild, so I'm glad I can buy raw absorption without the industry rituals and BS, like explaining what it's for before I can get a price, plus I like keeping the money at home (on AN). :)
Rich
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Thanks for the kind words. I've been an audio nut for years. Tough to have to hang on forums and help people learn what I learned the hard way. I do it because I enjoy it - and I learn things from other people too.
Oh, and by the way, some of the things on the site are priced the way they are because they're dictated minimums by the manufacturer. I list them as 'single piece pricing'. I offer discounts for quantity and for people on the forums I hang on.
That's about as much sales pitch as you'll get from me. :-#
Bryan
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Latest installment:
I built a little "house" out of acoustic panels, big enough to sit entirely inside it. I put it where it can remain standing for a while. Same parts, Infinity Entra 1 speakers, Cary SLI-80, home depot speaker wire, grovers white, SB3 running Inguz EQ plugin. I have to sit on the floor, because a 18" chair seat makes me too tall to fit inside the 48" ceiling. Still looking for well padded 10" chair. :lol: Maybe the bucket again???
The sound has taken another step forward, being in a larger volume there is less boomy bass, and more distance for the drivers to merge. EQing a little with Inguz dials it in nicely. I have never heard such a deep soundstage - at least in the center of the image. Sounds panned to the sides get magnetized into the speakers, I think due to their mid fi pedigree. The tweeter is a tough cookie to crack. I have some of the buzz knocked out of it with EQ, but there is no doubt it was designed for a larger space, and $150 price point. ;) It needs more distance than 18". Midrange sounds are awesome, very addictive.
I highly recommend tinkering with the Inguz EQ plugin, even if you don't use its room correction function, I haven't tried that yet. The plugin is very useful and I could hear no artifacts of processing, even in the electron microscope den of silence. It has "width" "balance" "quietness" and 6 parametric EQs. The only thing missing is Q adjustment for the EQs, but that would be asking a bit much. Nice job Hugh! It takes about 5-15 seconds for the EQ changes to kick in. Maybe a more powerful PC or more RAM would speed it up? I use P4 2.66GHz 333bus, 512RAM. With the slow response it helps to know how to EQ or else it will take some time to tweak. EQs can be saved as presets. Sonos can't do this!
The weirdest thing about this experiment is to listen to something with a huge ambient soundstage and "get into" the space, get totally convinced that you are there. Then after it is done, clap my hands to hear the real acoustic I am sitting inside of is totally dead, that is a mental shocker. I feel no need for more room ambience whatsoever.
I also like listening to the outside sounds in the silence between songs. Kids fighting, AC blowing, it is all 50dB down. But how do I fit my Legacys in there? haha Ventilation is also an issue.
http://www.parkwestlake.com/nopw/rich/anechoic2/DSC_7981.jpg
http://www.parkwestlake.com/nopw/rich/anechoic2/DSC_7982.jpg
http://www.parkwestlake.com/nopw/rich/anechoic2/DSC_7983.jpg
http://www.parkwestlake.com/nopw/rich/anechoic2/DSC_7984.jpg
Rich