Pulseaudio Crossover Rack - multi-way crossover design & implementation with linux

Member
Joined 2008
Paid Member
I really like the simplicity and elegance of PaXoR. It has been very stable since I started using it. My open baffle 2way speakers sound wonderful when turned up. :D

However I have been completely stumped by occasional pops in the playback. They only occur when PaXoR is activated. I’ve managed to get the system playing well enough that the pops are very infrequent and I’ve accepted them as inevitable at this point.

Something with squeezelite does not agree with PaXoR, but I’ve yet to isolate what is going wrong.

Perhaps the pending changeover to CamillaDSP will help. Regardless, thanks to Tfive for a great product.
 
Hello,
I have a question. I setup a crossover and really worked great. However, I want to use the crossover on my roon bridge and roon only accepts ASLA outputs is there any way to simulate PaXoverRack.input as an ASLA output so I can adress it with roon?


Sorry for the delay - once again the forum decided not to send out email notifications for this thread anymore :/


I don't know about other distros but linux mint has an ALSA device named "pulse" which can be used.
 
I really like the simplicity and elegance of PaXoR. It has been very stable since I started using it. My open baffle 2way speakers sound wonderful when turned up. :D

However I have been completely stumped by occasional pops in the playback. They only occur when PaXoR is activated. I’ve managed to get the system playing well enough that the pops are very infrequent and I’ve accepted them as inevitable at this point.

Something with squeezelite does not agree with PaXoR, but I’ve yet to isolate what is going wrong.

Perhaps the pending changeover to CamillaDSP will help. Regardless, thanks to Tfive for a great product.


Appreciated!


Regarding the pops... I don't get any pops or crackles on faster machines but still sometimes the synchronization between different paths throught the crossover is lost. Had I known in advance I had probably written a monolythic dsp engine with N inputs and M outputs back then, just what camillaDSP provides now but probably not so elegant. Had no time to continue on Pulseaudio Crossover NG in the last weeks but the project is still on my todo list.
 
On Manjaro (Arch ) roonbridge build files has--install socket by default systemctl -- global enable pulseaudio.socket + there is an upgrade .

All Arch type programming can be changed by user---and "destroyed " if not careful.

I only have ALSA installed though but along with a full range of libraries -compatibility-additional plugins etc-etc-etc.

A very long list of Pulseaudio exists if I want it.
 
duncan2 said:
On Manjaro (Arch ) roonbridge build files has--install socket by default systemctl -- global enable pulseaudio.socket + there is an upgrade .

All Arch type programming can be changed by user---and "destroyed " if not careful.

I only have ALSA installed though but along with a full range of libraries -compatibility-additional plugins etc-etc-etc.

A very long list of Pulseaudio exists if I want it.


I don't quite understand. Is there an install opinion for roon bridge to enable pulse audio when installing roon bridge?

That sounds like exactly what I am looking for but I couldn't find any documentation on install opinions could you maybe point me in the right direction? Or what would be the option to install with pulseaudio enabled?


I'm sorry about all the questions but I've been trying to figure this out for ages now.
 
Last edited:
I am running ubuntu 21.04 on a pi4. pulse comes up when I run aplay -L but the problem is roon seems to only recognize physical devices or in other words the "CARD"entries as shown by aplay -L. I think it would be necessary to trick roon into thinking that the pulse alsa device is a physical device.

I am sorry don't I want to bother you too much with this it basically a issue with roon. Your programm works flawlessly when I use librespot to stream spotify to my pi. Unfortunately the roon forum hasn't been very helpful people there are just like "pulseaudio has bad audio quality" ... which makes little sense.

Thanks a lot
 
Roon seems to only recognize physical devices or in other words the "CARD"entries as shown by aplay -L. I think it would be necessary to trick roon into thinking that the pulse alsa device is a physical device.

If that's really the case, it just shows the disadvantage of GUI-only configuration. Even the soundcard entry must be converted to a regular alsa device string by Roon. If the GUI allowed entering this string directly (as some override option), you could enter any PCM device defined in the alsa chain. BTW java in linux has the very same problem, the javasound alsa driver reads only the soundcards entries, not the PCM devices and there is no override of the device string. It clearly shows these projects are designed by people with very little linux experience.
 
I found a solution that isn't perfect but it works. I just reroute the sink to a loopback device using CamilaDSP. I know I could just do the whole process with Camilla but I simply didn't have the patience yet to get my head around the syntax for it. Also this way I know when you come out with a Camilla Version I won't have this problem any longer.

Thank you everyone.
 
Just a small teaser of the upcoming version with camilladsp backend... I'm currently in the process of rewriting the GUI widgets to support routing and mixing of individual channels, which up to now was a huge undertaking. That should be done in a few days of work. After that the actual DSP backend shoul not be too complicated. Fingers crossed :)

attachment.php
 

Attachments

  • PaXoverNG0.1.png
    PaXoverNG0.1.png
    154.5 KB · Views: 339
Is it fair to say that camilladsp replaces your previous LADSPA plugins and adds FIR capabililty?
Yes and yes.

I will first reimplement all the existing filters though, try to make config file creation and realtime parameter updates via websocket work reliably and then add FIR filters as one of the last steps.

There's still a lot to be gained besides FIR filters, namely more reliablility vs. the LADSPA plugins and arbitrary number of channels and mixing/routing capability. This would f.ex. also enable home theater setups with more than 2 channel stereo.
 
One more teaser... The graphical work is done, except maybe i'd like to make spline (connector) curves to have colors derived from input and output channels of a mixer... For example white/red in => mix to mono => pink. But that's a minor thing and in category nice to have, so I will leave it for now.

As I said, the UI stuff is done as far as I can see. That I think was the most challenging part. Now off to generate the damilladsp config, start/stop the process and a first version could be released to the public - albeit without realtime parameter changes. I will see how complicated that is - shouldn't be at all, so likely v1.0 also will have that in it.

attachment.php


PS: I'm aware that the shown filter configuration makes no sense at all, it's just for testing :D
 

Attachments

  • PaXoverNG_0.2.png
    PaXoverNG_0.2.png
    215.8 KB · Views: 309
Member
Joined 2008
Paid Member
I have a Debian installation without graphic environment installed. What would be the best way to use your GUI? Xwindow via SSH? It would be a "set and forget" thing, so I do not want to install anything extra. Or could it be done in a way that I would run it from the command line and then shutdown? So that it is not started at boot. I have CamillaDSP running as a system service starting before login. Only the "unfriendly" way of configuration is holding me back from using it.