Natural Science Forum / Physics / Acoustics / July 2007

I have a 4136 1/4 microphone that needs a preamp (and possibly an adapter).
I have a Bruel & Kjaer 2804 power supply or 2635 Charge amplifier available
as trading stock. My 2804 supports the longer Bruel Kjaer microphone
connector.

Split Faraday's Law -- the scientific concept of the Declaration gave me the
strength to speak, I argue a long-planned cut -- is a potential. Alternator
b. DC (commutator) c generators. d DC unipolar machines. No change to the
single-pole installations Motor http :

I'd like to see this paper, anyone now how to locate it?
                                               Mike
Dr. Joseph Pompei wins Technology Review's Award
for Audio Spotlight Directional Sound Technology

Hello group,
I am up against a factory ventilation noise problem. Vent outlets on
the roof are very close to a residential building. Noise measurements
completed by the inspector revealed a 200 Hz tonal component. Could

I have a poor quality recording of a mono-tonic drum rhythm (a
recording where no two notes occur simultaneously).
I wish to convert this recording to midi and then to use samples (high
quality) to reconstruct the recording.

How accurate is the human hearing with regard to time? I know that if
I quantize a midi file to the nearest 1/4 beat in a bar that I lose
the human feel in my music, but how small in milliseconds can I
quantize to without a human noticing much of a difference?

I've been trying to determine how to properly install a steel deck
with perforated webs so that the specified acoustic properties are
achieved.  I've read that there should be a rigid fiberglass board
above the deck, but does anyone know how thick or what density?

Hello, very armchair physicist here...had a question about an
observation I had.  Seems a bit odd...but it relates to the group...when
I am in a metal bathroom stall I find that when I hum certain
frequencies, the walls resonate and amplify the sound.  What is the

dear Pals:
Did anyone know the information about the insertion loss on RC tunnel.
We have some data from the ASHRAE and SMACNA. But they all for the
metal ducting.

Does any one know of a formula or a way to determine the resonant
frequency of a sheet of glass?
Ron

Hi, All;
More out of obsession than anything else, I've set about making one of
Star Trek's "Vulcan harps" more or less from the plans that are
floating around the Web. The harp is to have nineteen 0.017" strings--

I have downloaded a LD824 sound level meter. I was using it of FFT
mode with an accelorometer and preamp. The downloded details and in
dB. I want convert this to acceleration.
The sensitivity of the Accelerometer is 100 mV/g.

In my job, we regularly emit chirps underwater and record the
reflected sound.  To do this, we have a computer installed with a
function generator and oscilloscope card, which we connect to the
transducers using coax cables.  I was wondering if there is one

What is the pressure of a sound wave as a function of distance?  Where
does this relation come from?  I think it is
P(r) = 1/(4*PI*r)
but I can't seem to find any references to verify this.  I suppose there

I am working on a project concerned with sonoluminescence,in which we
have to create standing ultrasonic waves in water inside a 250cc
flask. Testing the piezoceramics I encountered with two problems:
1. The amplitude of the waves, which have been propagated to the water