Is running Headroom adjustment with PEQ detrimental to sound quality? Am I resampling/dithering the waveform twice? Should I just lower the overall gain in the PEQ setting, or should I use volume leveling?
What exactly does headroom adjustment do to the waveform? Am I clipping the low-level information?
There’s no mathematical difference between using the gain slider in the PEQ, headroom adjustment, or volume leveling. They are all the same code under the hood–each multiplies multiply the stream by a linear gain value.
This multiplication is information-lossless, since there is so much more precision in Roon’s intermediate 64bit sample representation than there was in the source material. I.e. if you have two gain adjustments and they cancel each other out, the output is bit-identical to the input (in the 64 bit domain).
The potential loss of precision comes at the end when the 64-bit internal representation is reduced to 16, 24, or 32 bits (and dithered) to feed your DAC. Generally, if the DAC supports a wider format than the source material, any reasonable combination of gain adjustments in Roon will be information-preserving. If they are the same, you might lose a small amount of precision, but it’s almost definitely deep below the noise floor of the room, and because of dithering, there are no non-linear/distortion effects associated with the loss.
I do not hestitate to use any of these features if they would in any way make my experience better.
I started to use PEQ and I set up 10 bands (with a maximum of -/+ 8db). I also use Volume Leveling.
So far I really like the benefits of PEQ but I noticed that, despite Volume Leveling activated, the clipping indicator is blinking sometimes…
My assumption was that we don’t need headroom adjustment with volume leveling activated… but it seems like I was wrong.
What is the safest level for headroom adjustment in order to avoid clipping? I set it up to -5b and, so far, I didn’t spot and clipping…
@Larry_Post Ok clear now. At the end I didn’t like much attenuation with the -22db so I changed the only band in PEQ where I added 8db and reduced to +5.
Then I set headroom adjustment to -5db and Volume Leveling to default -14LUFS. It sounds better for my ears
Very last question… having a PEQ band of -8db should not affect the digital clipping in my case. As I understand…only increasing volume may affect clipping. Am I right?