Convolution gain louder at higher sample rates

[Christoph Hart]

@d-healey Well the comment below the commit is correct, the problem is that you can't expect the linearity between resample factor and output gain - you even can't expect the gain change to be the same for each input signal, so it's a highly imprecise thing after all.

[lalalandsynth]

@christoph-hart I guess it would be helpful to have an approximation at least, I guess not many users are switching sample rates mid project?

[ustk]

Or getting a tool that tests different samplerates for an impulse and spits out a compensation table (why not an API we can directly use in script? but execution time might be a problem, or not with the new background thread...)

As @Christoph-Hart said it also depends on the input, but this is a lesser problem since users need to compensate for the signal they put in (as it's always been the case in any audio processing)

[d.healey]

What about providing several impulses at different sample rates and loading the one based on the "current" sample rate?

[ustk]

@d-healey I'm not sure this erases the gain problem, because you have to resample them somewhere anyway, but I might be mistaken...

[ustk]

Here's an interesting consideration in the last post:

https://dsp.stackexchange.com/questions/78354/is-it-ok-to-resample-impulse-response

My opinion would be to record them at different samplerates from the start, so you never resample, and load them as @d-healey mentioned
Although this might not fix the fact that regarding the frequency domain, you'll have additional energy in the upper frequencies at higher SR and so have to deal with (a filter might be enough though)

[ustk]

Could someone provide me with an IR at two different SR for which you approximately know the gain difference?
I'd like to make some tests...

[bendurso]

This is from two years ago, was there any change in Hise? I have this same problem.

Is it possible to decrease the volume of the Convolution Reverb samples with some configuration? So I could decrease the volume of the samples according to the sample rate.

[Dan Korneff]

@bendurso I ended up doing some calculations for the gain differences and threw it in a script.

[bendurso]

@Dan-Korneff said in Convolution gain louder at higher sample rates:

I ended up doing some calculations for the gain differences and threw it in a script.

Did you put a "Simple Gain" and modify it based on the currentSampleRate?

Because only the Wet signal is increased by the sample rate change. The Dry stays the same, and if I put a Simple Gain it will also impact the Dry signal.

[Dan Korneff]

@bendurso I did. I leave the convolution node set to full wet and mange the blend separately.

[bendurso]

@Dan-Korneff Cool thanks, I was learning scriptnode these days and I was able to do that. But how did you monitor the Sample Rate changes? In your last code post you were asking about that.

Making a timer to monitor the current sample rate would be another option to constantly output the values. Wouldn't there be any problem with this?