On Mon, 8 Feb 2010 18:25:43 -0000, "Serge Auckland"
wrote:


"Don Pearce" wrote in message
...
On Mon, 8 Feb 2010 17:43:51 -0000, "Keith G"
wrote:

Quite simply - allowing for the 'quite rapidly improving novice' playing,
which mic sounds the best on this instrument?


http://www.moirac.adsl24.co.uk/shown...0Webster-A.wav

http://www.moirac.adsl24.co.uk/shown...0Webster-B.wav


The difference between those two mics is totally drowned by a room
problem - namely a huge mode at 500Hz and about 1kHz. You may get some
preferences, but they aren't going to reflect the mics in any way, so
no selling on the basis of this test.

d

Don, how did you come to that conclusion? I've done an FFT of the track, and
don't see any great peaks. What should I be looking for?


You can hear it very clearly as a loud honk on track A. You can see it
too at the start of the first three phrases on the picture.

Also, 500Hz has a wavelength of about 69cm, so find it hard to see what
aspect of a room could have a mode at such a high frequency....unless the
mic was located in an alcove.

Yes it is a harmonic of some distance between two facing walls. Hard
surfaces will produce modes up to unbelievably high frequencies. Also,
it only needs a very small distance between mics for such differences
to show up when moding is the problem.

d