I'd expect it to expose the necessary bits already, but I suppose if you're using one of the hats with some controls for low level DAC chip options it might not have them. In that case you'd probably have to ssh in, or somehow install something like amixer-webui. I'm guessing though - it's not a distro I've tried as it used to be Roon-only, but XL might be worth a closer look.
Well, nothing much can be controlled - this is the interface for LibrespotI doubt you'll find either of those in alsamixer unless you start adding other things too, like adding alsaequal to the alsa config. Normalization really needs to be at the player level using metadata from the track or album - is there a librespot option that RoPieee isn't using?
librespot itself has come config options for normalization, so you may be able to mod RoPieeeXL to use those, or even present them in the web gui. If you can't do it yourself then ask in their forum - they might add it for you. The same might go for adding EQ options - I guess given that Roon has it built in at the server end it's not been an issue before XL appeared.
Tnx for your reply: I agree with you on the 'lossless' claim. Moreover I think, that MQA was/is trying to solve an issue that has basically disappeared: insufficient bandwith to stream highres audio files. In many countries you could stream in DSD/SACD quality these days - but then this is a proposition without a business case. I do not know how many subscribers ROON has but is a mere drop in the ocean of Spotify and the puddles of Tidal, Quobuz and Deezer.I'm not sure if Roon's DSP is inefficient, or if the powerful machine requirement is just covering themselves in case people try DSP on DSD in multiple rooms with different EQ. One of the CamillaDSP projects for LMS jokes about tasty looking CPU in such combinations while more 'normal' situations are MUCH less demanding.
It's certainly against one of the original claimed objectives of MQA, but do they still claim that, and is it any more believable than the original 'lossless' claim?
My understanding was that XL was for adding support for non-Roon sources, in which case adding EQ options for them seems within scope. I may be wrong - haven't used it or tried developing for it. Can't hurt to ask though.