Posted by Kenneth Sloan on July 24, 2001 at 23:10:55:
In Reply to: Re: Re: Re: more tuba spectra posted by Rick Denney on July 24, 2001 at 15:51:59:
Well, I've been doing this more or less "stream of consciousness", and I apologize to Rick in particular and other who may be misled.
The microphone used was the ATR-97. This is an Audio Technica mic - but it's a cheap "boundary" mike that is intended for computer conferencing applications. It's a disk about 2 inches across and less than half an inch high. I have it tucked away under my new computer display. (when you spend $750 for a 17" digital LCD display, you can't afford to spend $300 on a microphone!)
The recording was done by firing up Cool Edit (Rick is right - this is a good program), sitting down about 10 feet away from the computer (and mic) and playing one note, more or less stone cold.
It is, indeed, the F at the bottom of the staff, played (up to my usual standards) on a YBB-621S. This note tends to be sharp (for me, with my mouthpiece) - but I took no particular pains to play "in tune", or even check the tuning slide to see if it was in the "normal" position. Ambient temp was perhaps 82 deg F.
The clipping may be due to the cheap mic - or just my sloppy recording procedure. Tomorrow, I'll experiment with various controls (and get as far away from the mic as possible. The room is moderately live, roughly 20' square, with 8' ceilings clad in acoustic tile. The mic is on a table in one corner of the room (perhaps 2 feet from each wall) and I'll see what happens if I sit in the corner diagonally across.
What's the point? First, I think, is that the kind of effects that Rick talks about on his WWW page (The Tuba Sound) can be captured with even cheaper (and less expensive) equipment than he used. Second, it pays to be careful and remove as many obvious flaws as possible. As memory costs continue to plummet, I think the day is coming when any tuba put up for sale ought to be advertised with a recording of a 2-octave chromatic scale. A few mouseclicks can probably reduce this to a decent, moderately objective, description of the "sound".
My guess is that the best recording I can make will not produce a spectrum that looks appreciably different from this one. The clipping makes me very suspiscious of the peaks at 3f and 5f (and I'll work to remove this suspiscion) but quite frankly I'll be surprised if eliminating the clipping changes the evalulation.
Rick guessed that "it's not a tuba". Well...some people say that about the YBB-621S, especially when I play it. It's certainly not a York Master, eh?
On the third hand, now might be a good time to mention that I agree with a poster who gave the opinion that Rick's recordings might have been affected by his microphone placement. I'm particularly curious about the distances from the mic to the nearest reflective surface (walls, ceiling) and how that relates to the wavelengths of the harmonics that showed particularly weak peaks in Rick's spectra. Over to you, Rick...