[LAU] Jconvolver, IRs, and gain

[S. Massy]

On Thu, Mar 22, 2012 at 02:05:55PM +0000, Fons Adriaensen wrote:
> On Thu, Mar 22, 2012 at 09:35:48AM -0400, S. Massy wrote:
> > Hello,
> > 
> > I'm attempting to test some new IRs using jconvolver. I read the
> > instruction on the config file syntax and it seems straightforward
> > enough, and I am also using the hybridreverb.conf as a base template. My
> > problem is that the IRs I want to test are *much* louder than the
> > hybrid_reverb ones and are causing distortion when convolved. So far, I
> > went by ear and adjusted the gain to about 0.01-0.03, to a point where I
> > don't hear any distortion, but that got me wondering. Is there a better
> > way to estimate what gain setting to use from, say, the mean and peak
> > levels of the file? Is there such a thing as a preferred amplitude
> > range/peak for an IR? 
> 
> The 'normal' gain for a reverb IR would be such that the direct sound,
> if it were part of the IR, would have an RMS level of 1.0. On condition
> that the IR was taken with a source to mic distance that produces a good
> direct/reverb ratio. 
> 
> Another way to get reasonably good levels is to measure the gain
> using pink noise. Measure input and output with a RMS meter such
> as jkmeter. Note the difference, and adjust the gain in the config
> accordingly. 
Thanks, that turned out to be the quickest and most effective way to do
it. I unfortunately don't have an equivalent to jkmeter on the console,
but ecasignalview made a reasonable enough job of giving me a hint.

Cheers,
S.M.