On Fri, 31 Mar 2006 22:21:27 +0100, "Glenn Booth"
wrote:

Don't bother with room eq - it doesn't work, and it can't work for
very good reasons. Rooms are not unflat because of "frequency
response"; they are unflat because of standing waves or modes. The big
feature of these is that the response you measure at one point in the
room is totally different a couple of inches away.

Thanks Don. I wasn't planning to use it to EQ the room, just as a
blunt instrument to identify the problems; a sort of analysis tool. I'm
aware that EQ is not the solution.

OK - but you don't need special software - even Audacity which is free
will do. Generate a minute of pink or white noise and play it through
a speaker at reasonable level. Record it with a microphone in the
room, but *not* a stationary one. Walk around the room with it, move
it high and low, while you record. Then select the entire recording
and look at an FFT of the frequency response.

What that recording technique will do is remove any standing wave
effects and hopefully expose anything like a Helmholz resonator -
which is what you suspect the mezzanine is doing.

You will also see the frequency response of the speakers, of course.

d

Pearce Consulting
http://www.pearce.uk.com