Here is a quick link to HTS' room mode calculator.

Room mode calculator

The conversion tool is cooler.

Another nice room node tool

I had forgotten about Real Traps and you are right the conversion tool is cool.

That must be very nice for all of you with nice, uniform rectangular rooms.

I agree Tom, I wish some genious would develop a program that would let you plug in dimensions for l-shaped rooms, or account for vaulted ceilings.

I ran across a room simulator like that a couple of years ago. Problem is (IIRC) that since every point in the room sees different distances you need to iterate across a bazillion points then try to combine all the different results into something that might make sense to the user.

I ever-so-vaguely remember that it might have been from the company which supplies the microphone & software kits that Rives uses and recommends.

EDIT - there are a bunch of software packages available on the Rives Audio site. I think it was one of those but the quickie descriptions don't really say.

Here is the one I have used.

Can somebody refresh my memory about the room mode calculators.

How do you tell where the seat placement should be by these calculations? Say, for instance my room has the dimensions of 25' x 14' x 7.5 where would the seating need to be placed and how do you get that with these calculators?

Rick, you really don't get seating placement from mode calculators. They simply divide twice the dimensions of a symmetrical rectangular or square room into the speed of sound(about 1130 feet per second)to get the various room modes that result from sound traveling back and forth(that's why twice the distance is used)on each dimension. For example, your 25' length dimension results in the first length mode at about 1130/50, or 22.6Hz, with the next mode at 45.2Hz, then 67.8Hz, etc. The same is done for width and height. Problem frequencies where the various modes pile up are evident from this and possibly can be attacked by use of electronic room equalization and/or bass traps.

The only place where I have seen anybody use the room mode calculator for placement was on johnlsayers.com. He used the results to draw a grid so that he could identify tiny patches that were devoid of peaks and nulls and put his speakers as best he could in his studio.

Now thats dedication to good sound!