15 Oct
2013
15 Oct
'13
4:11 p.m.
Hey guys,
Which definition do you use when you want to do a gain control in dB?
GdB = 20log(Out/In) ?
10:26 p.m.
Thank you very much!
2013/10/15 John Rigg <ladev6(a)jrigg.co.uk>
On Tue, Oct 15, 2013 at 11:11:05AM -0300, André
Garnier Coutinho wrote:
Which definition do you use when you want to do a
gain control in dB?
GdB = 20log(Out/In) ?
Yes.
John
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10:41 p.m.
On Oct 15, 2013, at 10:11 05, André Garnier Coutinho wrote:
GdB = 20log(Out/In) ?
Close. You actually want:
GdB = 20*log10(out/in)
You probably knew this already as standard mathematical notation assumes log == 'log
to the base of 10'. However, the log() function in the math library will get you
natural logarithms ('log to the base of e'). You want log10(). Been there, done
that confusion myself… :)
Cheers!
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16 Oct
16 Oct
11:29 a.m.
On Tue, Oct 15, 2013 at 04:41:46PM -0400, Fred Gleason wrote:
On Oct 15, 2013, at 10:11 05, André Garnier Coutinho
wrote:
Good catch. I was thinking of the non-C convention of using log for base 10 and ln for
natural log when I answered.
John
GdB = 20log(Out/In) ?
Close. You actually want:
GdB = 20*log10(out/in)
You probably knew this already as standard mathematical notation assumes log == 'log
to the base of 10'. However, the log() function in the math library will get you
natural logarithms ('log to the base of e'). You want log10(). Been there, done
that confusion myself… :)
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4 comments
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André Garnier Coutinho -
Fred Gleason -
John Rigg