[It turns out this problem wasn't related to EQ at all, see my reply below.]
Anyone who's used EQ on other platforms knows you need to set the preamp gain to a suitable level when applying EQ boosts so that you don't produce clipping in the audio. Generally the preamp amount simply corresponds to the maximum gain in the EQ.
But I was doing some testing yesterday just to verify my setup with moode and it appears to need additional gain reduction to avoid clipping.
Here's an example in which I'm using my PC to record the output from my DAC just to check what's actually coming out. I checked with no EQ first and the gains were all fine with no clipping on a full-scale sweep.
First, I apply a +5dB boost @ 20Hz and a -5dB preamp gain.
It's clear that there's clipping in the signal. (This was also clear on zooming in on the waveforms.)
If I decrease the preamp gain to -7dB there's still a bit of clipping. Also note the glitch in playback that happened every time at this level:
But when I decrease still further to -9dB it's gone:
I use Sox (very high setting) to resample to 96kHz (this is to override the filter in my DAC), but everything else in the audio setup had been left at the default values. So it's possible there is some sort of weird interaction going on between the resampling and EQ that leads to a need for greater gain reduction. I have no idea what the cause of this is, but the easy workaround seems to be to reduce preamp gain by an extra 3dB or so.
Anyone who's used EQ on other platforms knows you need to set the preamp gain to a suitable level when applying EQ boosts so that you don't produce clipping in the audio. Generally the preamp amount simply corresponds to the maximum gain in the EQ.
But I was doing some testing yesterday just to verify my setup with moode and it appears to need additional gain reduction to avoid clipping.
Here's an example in which I'm using my PC to record the output from my DAC just to check what's actually coming out. I checked with no EQ first and the gains were all fine with no clipping on a full-scale sweep.
First, I apply a +5dB boost @ 20Hz and a -5dB preamp gain.
It's clear that there's clipping in the signal. (This was also clear on zooming in on the waveforms.)
If I decrease the preamp gain to -7dB there's still a bit of clipping. Also note the glitch in playback that happened every time at this level:
But when I decrease still further to -9dB it's gone:
I use Sox (very high setting) to resample to 96kHz (this is to override the filter in my DAC), but everything else in the audio setup had been left at the default values. So it's possible there is some sort of weird interaction going on between the resampling and EQ that leads to a need for greater gain reduction. I have no idea what the cause of this is, but the easy workaround seems to be to reduce preamp gain by an extra 3dB or so.
