Hi!

I have made myself an evaluation CD; a CD with snips from my CD
collection that could be used for evaluation of loudspeakers. A good
idea, by the way, that was inspired by some poster here at R.A.T.

I have decided to start the evaluation CD with a reference tone to set
the playback volume equal at every listening session. The problem is,
should I use white noise, pink noise, single frequency or something
else to set the sound pressure level? I have a lot of commercial test
CD:s to choose test tones from.

I have a simple SPL meter at hand, should I set that to linear, dbA or
dBC metering when caibrating the listeing level?

Per.

PS. It was fun to make the collection! It contains solo violin, big
jazz bands, Sheffield drums, "1812" cannons by Telarc and lot's more!

In article ,
says...

I have made myself an evaluation CD; a

I have decided to start the evaluation CD with a reference tone to set
the playback volume equal at every listening session. The problem is,
should I use white noise, pink noise, single frequency or something
else to set the sound pressure level?

Given that setting an absolute equal volume at multiple
points in the room is problematic at best, I suggest you
work from more of an "averaging" perspective.

As a reference point, use a music clip that is very highly
compressed, such as some currently popular "dance/trance"
music. The less volume variance, the better. Something
that varies less than +/- 1dB (using a slow-response meter)
would be good.


I have a simple SPL meter at hand, should I set that to linear, dbA or
dBC metering when caibrating the listeing level?

dBC, slow response.

--
Mark

The truth as I perceive it to be.
Your perception may be different.

Triple Z is spam control.

Per Stromgren wrote:

I have a simple SPL meter at hand, should I set that to linear,
dbA or dBC metering when caibrating the listeing level?

Set to SLOW and C, aim for 80 dB in the loud passages, that should keep
peaks at 105 dB or less and thus keep your ears in their reasonably
linear range, but verify the capabilities of amp and loudspeaker
combination, one loudspeaker powered by the amplification used should be
able to produce 105 dB peak at a distance of 1 meter.

Per.

PS. It was fun to make the collection! It contains solo violin, big
jazz bands, Sheffield drums, "1812" cannons by Telarc and lot's more!

Did you remember to check whether the source material is clipped ...
O;-)


Kind regards

Peter Larsen

--
*******************************************
* My site is at: http://www.muyiovatki.dk *
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On Thu, 02 Sep 2004 20:57:08 +0200, Peter Larsen
wrote:

Per Stromgren wrote:

I have a simple SPL meter at hand, should I set that to linear,
dbA or dBC metering when caibrating the listeing level?

Set to SLOW and C, aim for 80 dB in the loud passages, that should keep
peaks at 105 dB or less and thus keep your ears in their reasonably
linear range, but verify the capabilities of amp and loudspeaker
combination, one loudspeaker powered by the amplification used should be
able to produce 105 dB peak at a distance of 1 meter.

The CD has two track that I put there to be able to calibrate the
level: white noise at -20dBFS RMS and a 1kHz tone at -30dBFS. Is your
suggestion that I calibrate 1kHz at 75dB (equivalent to full scale at
105dB) and hope that 1kHz is not a severe dip or peak? Would white
noise at 85dB be better?

Per.

PS. It was fun to make the collection! It contains solo violin, big
jazz bands, Sheffield drums, "1812" cannons by Telarc and lot's more!

Did you remember to check whether the source material is clipped ...

I'm not sure I can! Are there any free tools out there, that could do
the job? I now Cool Edit can detect clipping, or guess rather, but I
don't want to buy a license.

Thank's for the comments.

Per.

Per Stromgren wrote:

Did you remember to check whether the source material is clipped ...

I'm not sure I can! Are there any free tools out there,
that could do the job?

Anything that can display the waveform on screen.

Per.


Kind regards

Peter Larsen

--
*******************************************
* My site is at: http://www.muyiovatki.dk *
*******************************************