I'm in the preliminary design of a HT and have some general questions. Is there an optimal ratio for the room design? What do I need to know (ie-no square rooms)? Are vaulted ceilings ok?

Scott

They are all ok ... the only differences would be what you'd need to do for acoustical treatments.

looks like I will be able to do a 14'x17' room with vaulted ceilings.

They are all ok ... the only differences would be what you'd need to do for acoustical treatments.

Totally agree. Just for the sake of information I'll add the following taken from Everest's Master Handbook of Room Acoustics, chpt 13, table 13-2 (H:W:L):

Septmeyer:
A - 1.00:1.14:1.39
B - 1.00:1.28:1.54
C - 1.00:1.60:2.33

Louden:
A - 1.00:1.4:1.9
B - 1.00:1.3:1.9
C - 1.00:1.5:2.5

Volkmann:
A - 1.00:1.5:2.5

Boner:
A - 1.00:1.26:1.59

Any of those ratios will work. Of course, it's kind of rare to run into situations where people have the freedom to adhere to those ratios, and like Dennis said, you can make just about anything work with the right treatment.

Frank

...and, contrary to some people's impressions, none of those ratios (nor any other ratio for that matter) will "fix" room modes.

contrary to some people's impressions, none of those ratios (nor any other ratio for that matter) will "fix" room modes.

Excellent point. Some people believe that a "good" ratio avoids bass problems, but that's just not true. You still have peaks and nulls and ringing. All a "good" ratio does is spread the modes out more evenly, to avoid two or modes at the same or similar frequencies. But those modes are still there and need to be deal with.

--Ethan