Acoustic Panels, Wow!

[JasonP]

So I went up to Lowe's and slapped together a 6 foot tall, 18" wide acoustic panel pair for the corners behind and near my bento boxes. I filled them with 3" R13 fiberglass roll, trapped between two twine screens (eyelets on the inside, feed through and made taught by hand), and covered them with some linen-style thin fabric from Joann's. The color is "potting soil", a deep in-offensive brown.

Then my mind was blown. Easily the best 70$ I've ever spend on audio. I'm not saying that they'd save a bad speaker, but the difference in voices in incredible. I sit here listening to Sarah Mclachlan and just have those shivers down my spine

I totally did not expect such a change in sound, and did it just to see if I could tame a ringing in my room at volume (which it indeed does help with).

How did other people's experiences with panels go? Any tips or tricks for usage or advice for placement of others? I'm contemplating a low-impact acoustic drop ceiling too now, since I found one I should be able to take out when I leave this apartment quite easily (I have to restore any changes when I leave).

[kevinr]

Re: Acoustic Panels, Wow!

Yeah , the room is definitely an issue .
found out when we got our old casement windows replaced a year and a half ago and there was no longer room for the pulldown pleated fabric window shades to fit in anymore in the music listening room .
Big sound difference, although there are cloth curtains on each side of the window in pullbacks , treble was pinging off the window glass just enough to be noticeable in an unpleasant way. I was a happy camper when I realized if I removed the top trim from the new window mount there was room to remount the shade.
Reinstalled the shades and it was back to perfect sound forever

[rpb]

Re: Acoustic Panels, Wow!

So I went up to Lowe's and slapped together a 6 foot tall, 18" wide acoustic panel pair for the corners behind and near my bento boxes. I filled them with 3" R13 fiberglass roll, trapped between two twine screens (eyelets on the inside, feed through and made taught by hand), and covered them with some linen-style thin fabric from Joann's. The color is "potting soil", a deep in-offensive brown.

Then my mind was blown. Easily the best 70$ I've ever spend on audio. I'm not saying that they'd save a bad speaker, but the difference in voices in incredible. I sit here listening to Sarah Mclachlan and just have those shivers down my spine

I totally did not expect such a change in sound, and did it just to see if I could tame a ringing in my room at volume (which it indeed does help with).

How did other people's experiences with panels go? Any tips or tricks for usage or advice for placement of others? I'm contemplating a low-impact acoustic drop ceiling too now, since I found one I should be able to take out when I leave this apartment quite easily (I have to restore any changes when I leave).

Did you see what I posted earlier today?

If you use typical insulating fiberglass with kraft paper backing, and leave the paper side toward the room, you will get lots of midbass and midrange absorbtion, with less absortion at higher frequencies. I did this once in the two corners behind the speakers covering about 6' of the 8' corner. It made a rather dramatic change in the sound of the room.There are some graphs showing absortion coefficients in "The Master Handbook of Acoustics".

If I wanted to make a quick and dirty absorber to test this again, I would take three six foot lengths of the fiberglass and tape them together along the 6' length. Basically make a 6' tube. Stuff the ends with more fiberglass, and stand them close to the corner of the room, with about 6" clearance between them and the wall.

[JasonP]

Re: Acoustic Panels, Wow!

No I didn't. I suppose great minds (or just ok ones!) think alike

[zerohourghost]

Re: Acoustic Panels, Wow!

Another great placement tip for acoustic panels is to take a mirror and go along the side walls starting at the speaker and moving away, and when you can first see the driver, put the acoustic panel there and you will kill reflections off of the wall. This will make a HUGE difference, Give it a try and you will not believe it! If you have a smaller panel put it at tweeter height.

[Starkiller4299]

Re: Acoustic Panels, Wow!

I <3 my panels as well. A couple of apartments ago, the living room had some wicked echo and ringing. 4 acoustic panels later, nada (well, at least dramatically reduced).

Say, when I get measurements going in the room, I'll take a few snap shots with /without the absorbers in the room. The current room isn't nearly as bad, though, so probably a bit more subtle in the differences .

[JasonP]

Re: Acoustic Panels, Wow!

Another great placement tip for acoustic panels is to take a mirror and go along the side walls starting at the speaker and moving away, and when you can first see the driver, put the acoustic panel there and you will kill reflections off of the wall. This will make a HUGE difference, Give it a try and you will not believe it! If you have a smaller panel put it at tweeter height.

The interesting thing about that suggestion is that I always believed we wanted the reflections from the side walls. I remember reading (possibly in a thread on this board) that: side reflections expand stereo image, and putting damping on the sidewalls is just like turning down the tweeter. I dunno, I've never tried side treatments. Sounds like an interesting experiment though.

[Pete Schumacher]

Re: Acoustic Panels, Wow!

The interesting thing about that suggestion is that I always believed we wanted the reflections from the side walls. I remember reading (possibly in a thread on this board) that: side reflections expand stereo image, and putting damping on the sidewalls is just like turning down the tweeter. I dunno, I've never tried side treatments. Sounds like an interesting experiment though.

Side wall reflections will destroy imaging queues. Nothing wrong with live walls, if there's plenty of diffusion going on.

[Face]

Re: Acoustic Panels, Wow!

Side wall reflections will destroy imaging queues. Nothing wrong with live walls, if there's plenty of diffusion going on.

I disagree, depends on the room/speakers.

[zerohourghost]

Re: Acoustic Panels, Wow!

I've got to lean towards the side of having panels, because I have noticed that reflections kill imaging and sound staging. I have the luxury of being not very far from one of the nations premier 2 channel equipment shops, Paragon Sight and Sound. They have Wilson Audio, Esoteric , Krell, Mcintosh, and the list goes on of equipment that can add up to more than a really nice house very quickly. Their demo rooms use acoustic treatments to get the most out of the sound. It helps with measurable accuracy if that's your thing which I like. But, it all boils down to how you like your equipment to sound in the room you have.

[[email protected]]

Re: Acoustic Panels, Wow!

please snap a pic or two of your placement in the corner as wel as in relationship to your speakers.

[JasonP]

Re: Acoustic Panels, Wow!

Pics or GTFO? :D

I have a home built 92" high contrast grey theater screen for my DLP projector covering most of the 11' wall, so I'm only left with a little space to apply any treatments around it. I'm sure though it absorbs something, since it a large frame with a an underlayment board atop it and then the screen

The speakers are 30" out from the rear wall and 22" from the sides, and I think IIRC the woofers are 34" up from the floor.

I put the panels right against the back corners flat on the rear wall, as so:





Here is a better look at the panels themselves, since they are kind of obscured by the artificial tree (which looks much better in room without a damn flash on it!).





As I mentioned before, its a thin linen material over a rigid pine board frame, filled with suspended R-13 acoustic batting (3.5" thick, kraft backed). I left the backing on the side that will be against the wall.

Oh, and yea, the book atop the Bento is because: I learned the hard way to model the baffle /before/ you build the speaker. I need +1" to avoid a terrible dip just above 2khz <.< I plan on adding a decorative name board to the speaker there at some point instead of the book.

[Pete Schumacher]

Re: Acoustic Panels, Wow!

I disagree, depends on the room/speakers.

If you have a tweeter, close to a wall, you'll get two apparent high frequency sources, and localization goes bye-bye in that case. Unless you drastically diffuse that reflected source, it needs to be absorbed, or localization is spread out instead of distinct. Without the localization queues, imaging is shot.

The farther away from the walls you can get the tweeters, the less it matters.

[Face]

Re: Acoustic Panels, Wow!

If you have a tweeter, close to a wall, you'll get two apparent high frequency sources, and localization goes bye-bye in that case. Unless you drastically diffuse that reflected source, it needs to be absorbed, or localization is spread out instead of distinct. Without the localization queues, imaging is shot.

The farther away from the walls you can get the tweeters, the less it matters.

depends on the room/speakers.

:D