Room acoustics, room size and dimensions.

krum · « **on:** 2 Jun 2005, 03:34 am »

Help!

My system is currently set up in a basement in a room that is 21' long; 13' wide and 7 and 1/2' in height (on one side the final foot or so of the lenght of the room has a height a little under 7 feet as a beam is boxed in). The walls are free-standing (fully insulated) and the floor is concrete, covered with padding and berber carpeting. I am considering increasing the size of the room and would appreciate any comments on the following--my concern is in regards to the fact that the width of the room would be close (thought not exactly) to "double" the size of the height. I am wondering if this ratio relationship would be a problem. Also, given the short height of the room does the following seem worthwhile?

I can move one of the walls to provide a width of just about 16'. This change would increase the total volume in the room by between 20% and 25%--I would need to box in some pipes along the ceiling about the last 1 and 1/2 feet and also box in a meter on the floor (about 1/2 way back along the long wall). Will the increased volume of the room be beneficial?

Regards,

Tim

warnerwh · « **Reply #1 on:** 2 Jun 2005, 05:54 am »

Room treatment will make your room act like a larger room and sound much better. Probably cost less also. If you can do both though.....

ctviggen · « **Reply #2 on:** 2 Jun 2005, 12:33 pm »

You might try downloading the mode calculator from here:

http://www.realtraps.com/modecalc.htm

I've plugged in your numbers, and the room with the lower width has fewer width and length modes under 200Hz. Additionally, the room with the higher width has one length and width mode right on top of each other (the one near 100 Hz).

I'd say try the smaller room, with some traps (either real traps or 8th nerve or both).

woodsyi · « **Reply #3 on:** 2 Jun 2005, 01:18 pm »

Tim,

It is important to consider treatment but don't forget speaker placement. My room is 16' wide and I barely have enough width to separate the speakers once I get away from the walls. If your speakers need to be away from the side wall, more width may by better.

ctviggen · « **Reply #4 on:** 2 Jun 2005, 01:26 pm »

Good point. I have my speakers set fairly wide, so wide that I bought 16 foot speaker cables.

woodsyi · « **Reply #5 on:** 2 Jun 2005, 01:50 pm »

Quote from: ctviggen

Good point. I have my speakers set fairly wide, so wide that I bought 16 foot speaker cables.

Bob,

Are you saying you got your 40's 10 yards apart? Where is your "nearfield" and how much do you toe in?

bpape · « **Reply #6 on:** 2 Jun 2005, 02:48 pm »

The greater volume can certainly provide some nice benefits -

Longer natural time for a single reverberation
Ability to place speakers farther from the side walls
Seating farther away from side walls
etc.

If the biggest you can go presents some potential issues, maybe try backing off 6 inches or so until you get something spread out further from a modal perspective.

In either case, treating the room will help tremendously.

Ethan Winer · « **Reply #7 on:** 2 Jun 2005, 03:19 pm »

Folks,

I agree with bp - when all else is equal, larger is better than smaller. Even when all is not equal - like smaller would have better mode distribution - larger is still usually a better choice.

--Ethan

ctviggen · « **Reply #8 on:** 2 Jun 2005, 03:23 pm »

My amps are near my right speaker. The cable for the left speaker runs all the way from the amp, across the room, and foward a few feet. The speakers are about 10 feet apart, but I also have a large room where I sit about 10-12 feet from the speakers. The speakers are also a few feet in front of the amps.

krum · « **Reply #9 on:** 2 Jun 2005, 09:02 pm »

Thanks for all the input. It seems that possibly the best answer is to go with the larger sized room and then use room treatments. This will be my most likley course of action.

Tim