Room Treatments for HT

[The Monkey]

I'm totally new to room treatments, so I'd be interested in any basic tips and advice about what works and what doesn't.

[naamanf]

http://www.atsacoustics.com/

Main idea is to dampen reflections. The above link has some good info and they also have decent prices on panels/traps. Also pretty helpful if you talk to them on the phone.

[ironbut]

A lot of what really works depends on the room you're setting up.

Ideally, any sound system is in a dedicated room or a room where you have carte blanche to do anything you want.

If you're able to, find the wall that works best (depends on shape and size of the room) to set up your speakers. For most folks, just doing that by ear is pretty painless.

Bass traps in the corners will help a great deal to even out the bass. Bass tends to build up in the corners.

Second, find the spot on either side of the listening area where the first reflections occur.

While sitting in the ideal sweet spot, have someone slide a mirror along the wall to your right until you can see a reflection of the speaker on your left. That's the spot where you should have some wall treatment (foam etc).

Repeat for the left wall.

It's also a good idea to treat the wall between the speakers and the wall directly behind you but the bass traps and early reflection treatment has the most bang for the buck.

[jvlgato]

I've had good luck damping the corners and the first reflection off the side wall.

 

You can buy the fancy stuff, but I just threw some rolls of home insulating material in the back corners behind some drapes. I did get an inexpensive acoustic panel (can't remember the brand now) for the side walls and located the position on the side walls by holding up a mirror on the wall and seeing at what location I can see the speaker from my listening position.

 

Probably there's much more sophisticated things you can do, but this was cheap and easy, and it worked pretty well for me in terms of controlling bass, cleaning up midrange, and improving soundstage.

 

Or maybe I'm just crazy, which is what my wife thinks ...

[deepak]

If you want to go nuts reading about it Ethan Winer's site has a pant load of information http://www.ethanwiner.com/acoustics.html#part1

 

And his commercial site has some more good info as well as videos: http://www.realtraps.com/

 

I personally found the biggest difference to come from putting bass traps in the corners and dampening side wall reflections. This is for my two channel system.

[aardvark baguette]

on one hand, you want to take into account that different materials will absorb different ratios of lows/mids/highs.  from what i understand owing corning fiberglass does a good job at absorbing fairly evenly for a very wide range (its what is used in commercial traps, with fabric)

on the other hand, putting a bunch of household crap into a room tends to make it sound better in my experience

 

i'm a big believer in diffusion on the backwall now, when I was in a small room that made the biggest immediate difference

large rooms are probably better served w/ damping (both being best of course)

 

i dont think you can ever go wrong with diffusion, but you can probably over-dampen if you're not careful.

Edited January 29, 2013 by aardvark baguette

[Dusty Chalk]

I just threw some rolls of home insulating material in the back corners behind some drapes.

I have to admit I liked this imagery. The fact that it makes sense just adds to the win. It's really not that different from what Ethan Winer will tell you to do. I may do the same thing, however putting some cat-scratch type carpeting over it for the cat.

Everyone else is offering good advice, too.

[bhjazz]

A lot of what really works depends on the room you're setting up.

Ideally, any sound system is in a dedicated room or a room where you have carte blanche to do anything you want.

Bass traps in the corners will help a great deal to even out the bass. Bass tends to build up in the corners.

Second, find the spot on either side of the listening area where the first reflections occur.

While sitting in the ideal sweet spot, have someone slide a mirror along the wall to your right until you can see a reflection of the speaker on your left. That's the spot where you should have some wall treatment (foam etc).

Repeat for the left wall.

It's also a good idea to treat the wall between the speakers and the wall directly behind you but the bass traps and early reflection treatment has the most bang for the buck.

This is excellent.  I completely agree.  

 

on one hand, you want to take into account that different materials will absorb different ratios of lows/mids/highs.  from what i understand owing corning fiberglass does a good job at absorbing fairly evenly for a very wide range (its what is used in commercial traps, with fabric)

 

i dont think you can ever go wrong with diffusion, but you can probably over-dampen if you're not careful.

Also good.  This is why I finally punted for my own room and called ASC.  The guy I talked to on the phone (at length, repeatedly) spent many previous years of his life working with audio, sales, etc.  Really knowledgeable and friendly.  And the ASC Tube Traps have some reflective and some non-reflective parts to the traps.  That way you can rotate them to dial in what works best for your room.  

 

On the diffusion side, adding some damping to the side walls is obviously good.  Keep in mind you can space two or more and begin to defeat comb filtering as well.  I hadn't thought of that until I spoke to the chap at ASC.  

 

I think the ideal spot for speaker placement differs for audio vs home theater.  Audio/stereo would bring the speakers out about a third of the room length in to the room.  Home theater would have them further back, close to the wall where your display is so that they diffuse more.

 

Along with the Ethan Winer site listed above, read up at ASC.  Lots of free and good info.  Also, here's ASC's HT site.  

 

I probably sound like a fanboy, but I get a lot more out of my system now that I have tube traps.  And whenever I think I'm fooling myself, I just take the traps out for a minute and realize how crappy the room sounds.  

Edited January 4, 2015 by bhjazz

[deepak]

The ASC stuff doesn't look too bad, I don't mind the look of the tubes behind the speakers.

[bhjazz]

They do have quite a few colors as well.  I mean, besides the obvious off-whites and all. 

[CarlSeibert]

I found that hanging a two foot by four foot panel of 705 about eight inches down from the ceiling at the first reflection point made a bigger difference than anything else I did in the Home Theater of the Absurd, which is a tiny little room, just filled with stuff. If you're short on places for panels and there's still a bit too much general purpose liveliness the ceiling is a handy spot. By being able to space the a panel from the surface I got good effect lower in frequency than I otherwise would have from a single thickness of 705. I think that's why that panel made such a big difference.