Local Monitoring on Raspberry Pi / Hifiberry with Jacktrip

[Larry Jordan]

Hello Experts,

I am wanting to do local monitoring with my Raspberry Pi 4 with the HiFiBerry DAC+ADC hat. I am using Debain and building Jacktrip for source and using QJacktrip for the UI.

My question is can I monitor the local input (guitar and mic coming in from an external mixer) and the Jacktrip session using the p2 option?

When I use alsaloop to enable monitoring on the Hifiberry the loopback is exactly what I want to hear. 

Starting Jack conflicts with the alsaloop access to the soundcard and I am wondering how can they share (not exclusive) or is there another approach I should consider and I have not delved much into more advanced setups as I am just getting to the ability to get hub sessions working with my group.

Of course my studio and server with the wonderful Focusrite interfaces all work with monitoring, etc. This is specific to the Raspberry Pi devices we have built.

Any guidance is appreciated.

Larry

[Hilpoltsteiner Michael]

Hello Larry,

if you are able to modify the jack connection in a way, that you route the capture signal (input) directly to the playback (output), then you get what you want. You could do that using QJackCtl or Patchage to create the routing and use aj-snapshot to save and restore the modified routing afterwards. I did that to include a compressor into the input channel. Please have a look at the following Debian packages, which you might need: aj-snapshot, lv2-plugin, swh-plugins, jalv, njconnect.

lv2 or swh plugins can be used to include an amplifier to be able to adjust the level of the monitoring signal.

Hope that helps,

Michael