Software Spectrum Analyser
 

In article , Arny
Krueger
wrote:
"Eiron" wrote in message


So would you use white or pink noise, or would it be better to use a
well-known piece of music, perhaps by Duke Ellington, to check the A
chain?

With modern technology, any source that is has significant content over
the desired frequency range can be used to calibrate a chain of
components. If you are working with acoustics, it might help if your
test source is not steady-state tones.

Depends. I recently did series of room+speaker measurements using a stepped
frequency series of sinusoids. Did this by playing the series and recording
the output of the player in parallel with recording microphone output. I
then did a series of correlations/FTs using the player output as
'reference' to let me extract the time delay as well as the amplitude. In
effect, a PSD technique. Worked quite well and the technique also
discriminated well against other background noises. I could use quite low
sound levels and still get good results. Also useful to assess the actual
level of distortion the combination delivers.

Slainte,

Jim

--
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Software Spectrum Analyser
 

"Eiron" wrote in message
...
David Looser wrote:
"Arny Krueger" wrote in message
...
A chain = record

B-chain = playback

????
No, all playback.

Imagine a typical "HiFi" system with a tuner, an analogue record player
and a CD player. The B-chain is the bit that is common to all, ie. tone
controls, power amps, speakers and room. There is a separate A chain for
each source though. For the record player that would be the turntable,
arm, cartridge and RIAA pre-amplifier.

The point is that the B chain only needs to be aligned once, by injecting
pink noise into a "flat" input of the amplifier and measuring the output
with a measurement microphone and spectrum analyser. That is then correct
for all sources. Checking for correct frequency response from the record
player, or the tuner or CD player can simply be done electrically at the
output of each respective A chain, the measurement mic and spectrum
analyser can be left in their cases.

So would you use white or pink noise, or would it be better to use a
well-known
piece of music, perhaps by Duke Ellington, to check the A chain?

--
Eiron.


Oh, very good!! :-)
S.
--
http://audiopages.googlepages.com

Software Spectrum Analyser
 

On Mon, 30 Mar 2009 19:18:45 +0100, David Looser wrote:

Can anyone recommend a good software audio spectrum analyser to run
under WinXP?

David.

Have a look at Virtins - the base level package is free. You will need a
decent sound card though. Some motherboards and laptops are too noisy.
Also, you'll find that software oscilloscopes can be a bit finicky above
10kHz or so as you normally have a sampling limitation of 44kHz - it
should be ok for sound measurement though.

Have fun. :-)

--
Mick (Working in a M$-free zone!)
Web: http://www.nascom.info
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