15 Aug
2006
15 Aug
'06
1:29 p.m.
Whoow , that was fast....
maybe i was a little bit misunderstandable.
when i wrote about jack, i meant the jackserver. i write an app, which has an
microphon input. now i will take this microphon signal and show it as a gain
meter. this is no magic and everything works.
if i understand all of you right, the pressure on the microphon is something
greater 0. and normally it is lower 2, right?
first question: is this the same pressure which is measured in the literature
in pascal (pa)
if so, its easy to calculate
out_value = 20.00*(Math.log(in_value/0.00002)/Math.log(10.00));
I know, i need to calibrate the room at the end. But in the moment, my
question is simply to get a signal and show the loundness in dbSPL.
Can i use the formula above or not?
thanks c~
Am Dienstag 15 August 2006 16:09 schrieb Steve Harris:
On Tue, Aug 15, 2006 at 03:30:47 +0200, conrad
berhörster wrote:
Hello all,
Does anybody know, how i can scale the incoming jack signals to dbSPL,
which is in the range of 0 to 120. An is it possible to calculate from
dbFS (which is used in normal soundapp in range -inf to 12db) into
dbSPL.
dB SPL is a measurement of physical sound energy, so in general software
was no control over it. It depends on the efficientcy of your monitors,
gain of your amps, desk etc.
The only way you can relate dB SPL to dB FS is by calibrating your
particular setup using a sound level meter. There's a SMPTE standard for
the relationship between dB SPL and dBu or dBv (I forget which), which
gets you half way there, but noone uses it anyway. I had my home system
calibrated to SMPTE for a while, and it was just anoying.