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Changing speed of groove~ also changes volume ?


May 26, 2010 | 10:08 am

Hi there,

It may seem as a newbie question but I have a weird feeling this morning.
When I change the speed of a groove~ object by sending a 2 to a sig~ I feel the volume is louder than the original speed.
Is it just a feeling or is it an natural acoustic fact ?
And is there like a mathematical relation between speed and volume in order to keep the same volume while changing speed ?

thanks a lot

May 26, 2010 | 11:58 am

there is a relation between pitch and loudness, but the factor depends on the
material and is not predictable.

just make some tests and find your personal value for lowering the gain (with
the desired effect on the percepted loudness) like say, -3db/A per octave …

-110
 

May 26, 2010 | 12:47 pm

thanks for your reply Roman
I will measure it with my material
but does it mean it is going to be a different factor if I play on another PA ?
thanks

May 26, 2010 | 2:13 pm

I think that this "material" Roman’s talking about is not your speakers but the samples you’re using. But I’m maybe wrong.

May 26, 2010 | 2:45 pm

I think he’s referring to this: http://en.wikipedia.org/wiki/Robinson-Dadson_curves

May 26, 2010 | 2:47 pm
May 26, 2010 | 2:48 pm

oops, looks like we had the same idea. ish..

May 26, 2010 | 6:50 pm

very interesting readings…
thanks guys !
that’s exactly what I was looking for

May 27, 2010 | 1:23 am

fletcher munson, no not exactly what i was thinking of.
because it wont really work for broadband audio like say, a piano sample or a drumloop.

May 28, 2010 | 7:40 pm

if you know the playback volume, maybe you could use a weighting-filter to calculate the perceived loudness and compensate for that…??

http://en.wikipedia.org/wiki/Weighting_filter

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