Librem 5 Evergreen Headphone Jack not compatible with certain audio connections

Environment: headphone (bose quiet comfort 15 etc), librem 5 evergreen, shortwave music app.

Steps to repeat:

  1. plug in headphones,
  2. start shortwave app, play music,
  3. open gnome settings sound

Observe sound is correctly routed to headset (external), also observe no sound on headphones.

Issue: The librem 5 supports 4 pole 3.5mm audio male jack connectors, the L5 does not seem to support certain 3 pole headphone jack connectors e.g. Bose Quiet Comfort 15.

Why is this an issue: Most headphones and other receiver audio equipment is 3 pole not 4 pole (only used in headsets with microphone i believe).

Question: Since the audio jack was supposed to undongle users lives, it goes against my better judgment to buy a dongle that converts female 3 pole to male 4 pole. Is there a software solution that could combine channels to get audio output (in my case it may be switching the ground with aux)?

I don’t think that statement is correct.

I have standard headphones (3.5 mm TRS plug i.e. 3 pole) and they work just fine with the Librem 5.

My Apple earbuds (3.5 mm TRRS plug i.e. 4 pole) also work fine with the Librem 5 for sound output.

Testing with: Lollypop

I believe that the connector in the Librem 5 is 3.5 mm TRRS. However I have often found standard headphones to work correctly when plugged into such a connector. Conversely, I can plug a full headset (headphones and mic) into a classic audio output (green) socket and audio output still works. (In other words, the mic is added in such a way that sound output continues to work even when the mic is not supported by one end.)

I believe that sound input via the Librem 5’s TRRS connector is not yet working - coming soon.

In conclusion, I suggest you investigate some more.

PS Yes, you can get a short combiner cable (no smarts, electronics, dongle, … needed) that turns a microphone plus headphones into something that could be plugged into a TRRS socket but I don’t think that should be necessary. To be clear 2 x TRS female to 1 x TRRS male.

You can also buy the reverse i.e. a short splitter cable - 1 x TRRS female to 2 x TRS male but that isn’t relevant here.

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it might depend on where the ground is placed in the socket.
The mic would have to be deactivated if it has the same potential as GND. I don’t know if this is possible.



P.S. my akg headphones are working fine.


L5 does support 3 poles. Tested with multiple headphones. No problems observed.

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Hmmm i wonder then what are the odds, my Bose 15 3pole headset doesnt work, and i used my old yamaha receiver with a 3 pole jack (that works fine on my bluetooth receiver adapter) and that doesnt work either. However the purism headphones 4pole worked just fine.

Also remember to consider/ruleout that there is a glitch with your phone (jack or further in).

sure but it works with 4 pole, a wiring issue wouldnt that cause that to not work? i might test doing a call with external mic to see if that works.

thanks glad to hear it is supposed to work at least

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It works, but needs to be manually selected in settings right now. We’ve just got automatic detection to work a few days ago, and there are audio quality improvements in the pipeline as well, but those haven’t made it into any release (or even got merged in git) yet.

BTW. Yes, TRS headphones are supposed to work and do work fine here. With such plug, it’s the microphone pin that gets grounded, so output pins are not affected.


Good News: Ok maybe there was some contamination in the L5 socket but after going through 5 headphones that i have and re-testing my bose 15 that come with 3 pole and 4 pole 3.5mm jack cables and they both work now!

Good News as Well: the L5 does support all TRS cables. I have a TRS to RCA (red, blue) for my stereo receiver Yamaha HTR-5930, and for some reason while it initially failed to output sound my receiver now picks it up. Probably the same issue as above that after jack use whatever was blocking the signal, contamination was removed by plugging and unplugging the connector ~ 20 times.

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Maybe. I’ve seen that with a classic computer 3.5 mm audio output (green) socket on another (completely unrelated) computer. Connect to earbuds and it works fine. Connect to some external speakers and no sound.

I think you would need to understand what the cable is doing and whether you can get some kind of adapter that does this properly.