Author Topic: An experiment  (Read 18453 times)

lonewolfny42

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Re: An experiment
« Reply #15 on: August 17, 2007, 11:42:45 PM »
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 ?

Offline Carlman

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Re: An experiment
« Reply #16 on: August 19, 2007, 07:45:15 AM »
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
I really enjoy listening to music.

Offline rollo

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Re: An experiment
« Reply #17 on: August 20, 2007, 06:37:49 AM »
Rich,
          Really well done man. I thought I have seen it all.


  rollo
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Offline bpape

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Re: An experiment
« Reply #18 on: August 20, 2007, 06:52:54 AM »
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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Offline richidoo

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Re: An experiment
« Reply #19 on: August 20, 2007, 07:13:42 AM »
Thanks, glad I could be of service. :D  Wait til you see the next experiment.

Offline richidoo

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Re: An experiment
« Reply #20 on: September 09, 2007, 01:27:15 PM »
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

Offline richidoo

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Re: An experiment
« Reply #21 on: September 09, 2007, 03:17:17 PM »

Offline bpape

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Re: An experiment
« Reply #22 on: September 09, 2007, 08:09:24 PM »
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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Offline richidoo

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Re: An experiment
« Reply #23 on: September 09, 2007, 10:25:27 PM »
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

Offline bpape

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Re: An experiment
« Reply #24 on: September 10, 2007, 04:06:35 AM »
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
I am serious... and don't call me Shirley

Offline richidoo

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Re: An experiment
« Reply #25 on: September 10, 2007, 06:02:41 AM »
Very cool. BTW, Do you have a biz website Bryan?
Thanks
Rich

Offline bpape

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Re: An experiment
« Reply #26 on: September 10, 2007, 06:15:42 AM »
Clickie my globe icon under my avatar.

Bryan
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Offline richidoo

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Re: An experiment
« Reply #27 on: September 10, 2007, 01:00:48 PM »
 :duh

VVVVVVVery nice. Thanks

Offline bpape

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Re: An experiment
« Reply #28 on: September 10, 2007, 01:02:57 PM »
It still needs some work but things have just been crazy busy lately. 

Bryan
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Offline richidoo

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Re: An experiment
« Reply #29 on: September 10, 2007, 01:12:50 PM »
Any nicer and you would have "too much" biz. haha