Room Treatment Alternatives...

[superpanavision70mm]

So, everyone knows how important that doing room treatment can be, but most people have a hard time justifying spending so much money on what essentially looks like it cost about $3 to manufacture.

Here's the question....

Is it possible to come up with some alternative room treatment solutions that at least make the room improve over doing nothing at all, which is the worst case scenario? I have certainly found a few ideas in my brief history....

blankets and rugs are usually one quick method...anyone else have some ideas?

[Jimmy C]

So, everyone knows how important that doing room treatment can be, but most people have a hard time justifying spending so much money on what essentially looks like it cost about $3 to manufacture.

Here's the question....

Is it possible to come up with some alternative room treatment solutions that at least make the room improve over doing nothing at all, which is the worst case scenario? I have certainly found a few ideas in my brief history....

blankets and rugs are usually one quick method...anyone else have some ideas?

...to deaden the sound a bit, decorative wall hangings are one way to go. Placing them at first reflection points coud be a big help.

On the flip side, a room that is TOO dead is undersireable as well. That can suck the life out of the music. I've heard the B&W 805s in a few different stores, on one occasion the speakers were placed in a tiny, super-damped room. There was almost no presence at all, just fuzzy bass.

Also, you can simply play around with speaker placement.

Good luck...

[Sir Terrence the Terrible]

The problem is you do not know how these things will eventially effect the sound in the room. We know that blankets and tapestries obsorb sound, but how much does it obsorb? Does it reflect any energy? How does it scatter? At what frequencies does it effect/obsorb?

In other words using non traditional acoustical control tools leaves alot of questions open, and does not have predictable results like traditional acoustical controls have.

Also everyone seems to think obsorb, obsorb, but there are diffusion and reflective properties that also must be taken into consideration in any room. It is all a balance between controlling reflections, and creating a spacious sound as well.

Do not assume you have to do nothing but obsorb reflections.

[Jimmy C]

The problem is you do not know how these things will eventially effect the sound in the room. We know that blankets and tapestries obsorb sound, but how much does it obsorb? Does it reflect any energy? How does it scatter? At what frequencies does it effect/obsorb?

In other words using non traditional acoustical control tools leaves alot of questions open, and does not have predictable results like traditional acoustical controls have.

Also everyone seems to think obsorb, obsorb, but there are diffusion and reflective properties that also must be taken into consideration in any room. It is all a balance between controlling reflections, and creating a spacious sound as well.

Do not assume you have to do nothing but obsorb reflections.

...the poster didn't seem like he wants to get too technical, IMO he simply wants to hear more of the music, not the room. One doesn't need to spend a lot of dough to get better results.

If I simply take out the four bath towels my wife and I use in the bathroom, I can hear much more echo when talking, whatever (hhmmm... why would I be talking so much in the lav?) . Anyway, that's what you want to minimize... slap echo... and you don't have to go crazy to get it somewhat under control.

You know the drill... clap your hands and see how much "ringing" there is. My bedroom has a fair bit more than the livingroom, I suppose due to being smaller, as well as not having curtains. Oh, also no throw pillows, along the walls on top of the sofas. Whatever... everything sounds pretty good.

Time to spin some vinyl, my 'lil Bellari is warmed up :^)

[Woochifer]

Given how many threads on this board over the years have discussed system upgrades with most of the posts not mentioning room treatments at all, I'm not so sure that the importance of room acoustics has sunk in with everybody. If anything, it takes a lot of convincing before most people will look into room treatments instead of dumping money into upgrading amplification, source components, cabling, or power conditioning yet again. Once the message gets through though, pretty much everyone buys into how important an effect the room acoustics have.

As for the room treatments themselves, there are many approaches, levels of effort, and outcomes. Before anyone even gets started on room treatments, they need to figure out what the problem is. The drawback to stuffing a room full of absorbing material is that the room might not need it in the first place. Homes from the 60s and 70s with acoustic ceilings, while suffering aesthetically, already have very effective diffusion in place. Add some thick pile carpeting and a lot of cushy furniture, and that room might not need any more aborption. If you don't hear any "slap echo" the room might already be in decent shape. Overdoing it with the absorption can drain the life out of the music.

A room full of hard reflective surfaces will likely benefit a lot from rugs and wall cloths, among other things. Anything that breaks up or absorbs the first reflection, so that it does not bounce back to the listening position at close to full volume will reduce the interactions that can make the sound seem harsh and unfocused. Reflected sounds that interact with the direct sound within about 5 ms of one another will be interpreted by the brain as a single sound event, i.e. a time domain distortion, so the key is to make sure that the reflections get redirected somehow.

But, as Terrence referred to, different materials will have different absorptive properties at different frequencies. Generally, wall cloths will absorb the high frequencies, but be relatively ineffective from the midrange on down. Thicker rugs might go further into the midrange, but simple building materials like fiberglas boards or panels used in suspended acoustic ceilings will likely have more consistent sound absorption throughout the high and midrange frequencies. Plus, unlike with rugs or fabrics, building materials from Owens-Corning or USG are often rated for their sound absorption by frequency range.

Commercial room treatments cost more because they are even more consistent in their absorptive properties, and many of them are effective into the lower frequencies, which rugs and ceiling panels are not. They are also often controlled for a specific absorption curve, which is what you'd want if the room is being tuned by an acoustician.

Room treatments don't have to cost a lot. A box of ceiling panels that I used in my first experiments with room treatments cost only $16, and just lining them up around the room measurably reduced the reflected sound that bounced back to the listening position while subjectively giving the imaging a much sharper focus and providing a noticeably smoother sound overall (this will look very ugly, so I later dressed them up using fabric and a glue gun, and suspended them from a picture molding). Jon Risch's site has some approaches to making acoustic panels and bass traps out of building materials. Home Theater Hi-Fi did a roundup of commercial room treatment products a while ago as well. For anyone interested in learning more about room acoustics, F. Alton Everest's Master Handbook of Acoustics is a must-read.

http://www.geocities.com/jonrisch/a.htm
http://www.hometheaterhifi.com/volum...04-part-1.html
http://www.powells.com/cgi-bin/bibli...2-0071360972-0

Diffusion is often recommended for the backwall and the side walls. There are diffusor products out there, while the more improvised approach would be to use a large bookshelf and fill it with books of different sizes to create an uneven surface that will break up the sound waves.

Aside from issues with the absorption, there's also the boundary effects to consider. These primarily affect the lower frequencies, and the smaller the room, the more pronounced the boundary effects are. The room boundaries will reinforce the lower frequencies, and this reinforcement begins at a higher frequency as the room dimensions shorten and increases in magnitude as the frequencies go lower. With the lower frequencies, you deal with the room induced effects through a combination of placement (the location of the subwoofer and/or speakers relative to the listening position), bass traps (so that the corners don't reinforce the low frequencies at full amplitude), and equalization (attenuate specific problem frequencies at the listening position).