# Annoying room resonance... how to get rid of it?



## SQBubble

The more I listen to the B&W 685, it gets annoying, not because of the speaker, because of the room. I don't know what it is exactly, but I think it's in the mid-range or high mid-bass. It resonate and it sounds oh not so good. When I put the speakers in the living room, it sounds amazingly better, a lot easier on the ear, imaging is super wide, very spatial. But in my little room, it does sound good at low volume but when I turn it up, its like multiple resonant sounds merge together and ruins the original music/movie soundtrack... 

Is it the small room? or the walls? is it possible to repair this problem?


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## Kal Rubinson

1. Small room
2. Probably not if the frequency is low. Possible.
3. Wide-band bass traps.

Kal


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## hjones4841

I am sure that others will chime in with more info, but it sounds like your room is a candidate for acoustic treatment. This is re-inforced by your speakers sounding better in one room than this one. Hard surfaces (wood floors, sheetrock) bounce sound around and blur speaker imaging. Also, smaller rooms have more uneven bass response due to widely spaced room resonances (modes) that are a function of room dimensions.

There are remedies that may fix the problem, but unfortunately predicting the effects is inexact. You just have to try and see what works. 

Many favor placing absorption panels on the side walls at the first reflection point. The first reflection point is the place where your main left, right, and center speakers' sound first bounces from the wall and arrives at your ears. Although a room will have many bounces, the first one tends to be the most noticeable to the ear. Absorbent panels mounted on the side walls are effective in reducing the amplitude of the bounce. They come in various colors and are usually 2' x 4' and 1", 2" or 4" thick. Pricing starts at around $30-40 for the thinner panels. These should improve your speaker's perceived imaging. I have had first reflection panels up for several years and they made a definate improvement in my room (12.5' x 20.5' x 8'). You select the place to put them by sitting in your favorite chair and have someone move a mirror around on the side walls. When you can see your speaker in the mirror, that is the place to put the absorption panels.

Treating a room for bass frequencies is different and often requires bass traps, which tend to be thicker (4"-7" and more) and are usually spaced away from the wall to increase the trap's efficiency. I am a recent convert to bass trapping and I can tell you that it makes an amazing difference in bass smoothness and transient response (kick drum, electric bass, etc.)

Anyway, that is a start. There are many on this forum much wiser than I on room acoustics and I am sure they will be happy to answer questions and offer advice.


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## bpape

If you can post the dimensions of the room and maybe a couple of pics, that would help. In a small room, broadband bass control is very important.

Also, if the room is narrow, speakers tend to be closer to side walls which can cause boundary issues in the bottom end giving ragged frequency response with large peaks and nulls. A thicker panel directly beside each speaker can help minimize this issue.

Bryan


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## SQBubble

ok my room is 125"wide, 120"deep and 100" tall (~10.5' x ~10' x 8.33' ), my room peak is at around 53hz and nulls between 58hz and 100hz...

this is the FR of the B&W 685 with no eq full-range:










this is a decent pic that fills the whole room kind of....:










more pics can be seen here:
http://s105.photobucket.com/albums/m239/SQBubble/Home Audio Project/?start=all



thx for the info hjones, ill look into absorption panels, the bass isnt really a problem, i can eq down the 53hz peak, i would really like to have better output in the mid-bass/upper bass region, but i can live with it... its really in the mid-range , theres that ringing sound, especially when playing some radiohead or some sort...


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## bpape

Hard floors will do that. Try a rug - seriously.

Also, with the speakers right against a wall (and one in a corner) you're going to get all kinds of irregularities as you're seeing due to boundary effects. Treating those surfaces will help minimize those issues as well as tame the room where you're concerned about.

Bryan


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## Kal Rubinson

In addition to room surface and bass treatments, you might get the speakers off the tables and out of the corner.


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