Crossfeed

[dosenfisch]

Is it possible to implement crossfeed in the audio path of Pandora 2?


I think it's one of the most useful features of headphoneamps and the only thing I realy miss in the actual Pandora in terms of audio quality.

 

[Znirk]

Can I just get some clarification here: You'd want a couple of mixers added to the analog stages of the audio hardware?


I don't think that would be a use of space, money and design effort which justifies the result. The pandora, current or 2, can perform crossfeed in software, on the digital side of the signal, with a lot of potential for tuning the details to the individual user's taste. I don't yet have a pandora, so I don't know if any software already offers this; but the capability is certainly in place.


If no player with crossfeed exists yet, asking for someone to build a crossfeed mechanism into your favourite player application seems like the more promising approach than asking to add hardware. Maybe you could even do this yourself? I don't know what kind of time and skills you have; but it's unlikely you'll ever find a DAP where it's as easy to run your own code as on the pandora. Learning opportunity, maybe?


But if you categorically can't live with digitally-processed crossfeed at all, I suggest you continue to carry that headphone amp with you.

 

[dosenfisch]

The problem is not the quality of software based crossfeed in general, but modifying every peace of software using sound is not possible.


All the emulators, games, etc. still won't support it and carrying an extra headphone amp just makes the Pandora less portable.


I'm not sure how much effort it really takes to modify the audio path, but according to this schematics, its no big deal in terms of space or components.


But don't get me wrong, it's just an idea how to improve sound quality a bit further.

 

[Znirk]

Huh ... OK, my one application for crossfeed is to listen to hard-panned recordings through headphones without developing a headache. Why do you need crossfeed on emulators and games?


Adding software crossfeed into the system-level mixer software might be quite feasible, actually. What kind of audio system does the pandora use?

 

[fahrstuhl]

That should actually be possible by editing the ~/.asoundrc file. One could do something similar to this: http://alsa.opensrc...._stereo_to_mono


I haven't tested this yet but I think it could work like this:

pcm.crossfeed {

type route

slave.pcm "softvol"

ttable.0.0 1 # Maps channel 0 to channel 0 at 100% volume

ttable.1.1 1 # Maps channel 1 to channel 1 at 100% volume

ttable.0.1 0.3 # Maps channel 0 to channel 1 at 30% volume

ttable.1.0 0.3 # Maps channel 1 to channel 0 at 30% volume

}

pcm.!default {

type plug

slave.pcm "crossfeed"

}