"Don Pearce" wrote in message
...
On Tue, 6 Mar 2007 13:39:14 -0000, "Serge Auckland"
wrote:

I have done some measurements on my listening room and would welcome some
comments an advice.

The low frequency response of the room as driven by my 'speakers is :-

http://audiopages.googlepages.com/Sp...enmic-full.jpg

If anyone would like to replicate the FFT, the original WAV file is:-

http://audiopages.googlepages.com/whitenoiseopenmic.wav

Microphone was the one fitted to the Radio Shack Sound Level Meter, used
with the output taken to my sound card and recorded in Cool Edit. SPL was
70dBC.

From what I've seen, the room response looks pretty reasonable, so I'm
happy
there. Go on, disillusion me.......

OK - here goes. Play a constant 150Hz sine wave tone through your
system. Now walk back and forth along and across the room with your
level meter and check how much it goes up and down. As you approach a
dip, slow down and move the meter gently in all directions (including
up and down) until you find the lowest level. How far is that below
the loudest part?

That will establish the level of standing waves in your room. In a
decent room, that should be comfortably less than 10dB peak-to-dip.

d

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

Certainly isn't within 10dB! More like 22-23 dB peak to dip, but much more
dip than peak. In the main listening area, the swing was smaller, around
16dB Peak to dip, and again, few peaks and that of only around 6dB, but some
quite deep dips. I did the test at 160Hz, as that's what is on my
(home-made) frequency test CD 1/3rd octave ISO frequencies.

Why did you chose this particular frequency?

S.