Posted by Rick Denney on February 13, 2001 at 14:18:32:
In Reply to: Practice Room posted by Long time lurker on February 13, 2001 at 13:48:39:
I think you have to decide what it is that you don't like about the room. There are several possible faults:
1. Echo. This is annoying. But it's easy to identify. Snap your fingers as you walk around the quiet room. Do you hear your snap repeat several times? The delay will be extremely short, because the room is small. This is caused by flat, opposing reflecting surfaces, like walls, and the floor/ceiling combination. Echos are easily fixed by covering one of the reflective surfaces with a shape that disperses the sound in all directions rather than straight across to the other surface. For example, hanging a drapery on one wall will usually eliminate the echo. I solved an echo problem by hanging a rug, tapestry-style, on one wall. Note that it does not absorb sound, rather it diffuses it.
2. Reverberation. This is the after-glow of sound that persists for a second or two after you stop playing. This is a good thing. If you have it, thank your lucky stars. The difference between reverberation and echo is that reverberation is a smooth fall-off of sound, rather than repeated sound images as with echo.
3. Deadness. The opposite of reverberation. This happens in rooms that have been covered with egg-crate substances, and so on. It's fine for a radio-station studio, but for tuba playing it's tubby and unappealing. The solution is to increase reflective surfaces, but not such that they are parallel, or you'll get echo instead of reverb. A rug on the floor and a hard-surface ceiling might give you a better sound than the current hard floor and soft ceiling. Deadness is a pain--it exposes every last fault in your sound. On the other hand, maybe it's not so bad, as long as your ego can handle it. Low ceilings are a particular culprit here.
Any of these characteristics can exist at different frequencies. You can have a room that is live in the bass frequencies and dead in the treble overtones. This makes your tuba sound tubby. Increase hard-surface reflectivity to absorb fewer treble frequencies. Or, your can have a room that is too live or echo-y in treble frequencies and dead in bass frequencies. This gives the room a crispy-fried brittleness that is annoying. This was the problem I solved with the rug on the wall in my house in San Antonio. In a small room, a certain deadness is expected and hard to resolve. Just be aware that you'll sound better in any performance venue.
Oh, and make small changes incrementally. You can go too far and create a worse problem.
Finally, just so you'll know, this has absolutely nothing to do with sound-proofing the room. That is a wholly separate issue with nearly no overlap with this issue.
Rick "a spectrum analyzer will tell you which frequencies are live" Denney