I get a lot of noise when recording audio via a microphone in headset plugged into the 2.5mm jack. The very same headset gave me much less noise when used in my old Thinkpad laptop (with literally the same software since I just transferred the SSD from the Thinkpad to the Librem mini) and in my tablet.
Has anyone noticed a similar problem? Any idea how to reduce that noise?
No, no, the problem appears with all microphones, and shows much more noise then when the same microphone is connected to another machine. It really looks like a problem within the Libre mini itself.
FWIW, while I have no idea where this noise comes from (seems to be due to faulty (or maybe badly initialized) hardware), I did find a partial workaround. I added the following lines to my /etc/pulse/default.pa:
and after rebooting, I now have an additional audio input which has some kind of echo cancelling, and that seems to help. I’ll see if my students also think the result is now acceptable (it clearly wasn’t before).
To me it sounds exactly like a noise cancellation issue. I can only say that while your software is the same, your hardware is not. It is possible that your thinkpad had hardware geared towards noise cancellation or the mic wasn’t as sensitive, etc, that your mini does not.
Although to be honest, I wouldn’t be using the base mic to begin with. I’d probably look at a USB solution in conjunction with a webcam. That might be a quicker solution.
I still think it’s a problem in the Librem mini: that very same microphone connected in the same way and used at the exact same place gives perfectly acceptable results when connected to my Android tablet as well as either of the laptops (Thinkpad X201 and Thinkpad T61) with which I tried (all 3 non-Android machines running the same Debian testing).
That is what I was saying as well. Your hardware is the only variable that is different. Circuits are specific things. They behave exactly the way they are designed. If the tolerances for noise in the mic circuitry on the mini are different than those on your thinkpads (each designed specifically with conferencing in mind) then you will notice audible differences. This is to be expected.
What you are hearing here as noise, is most likely the differences in the designs of those circuits. Fortunately dsp has come along way and most circuitry failings can be overcome in software.
Now whether your device is faulty, I can’t say. I would suggest contact Purism directly for support.
if you’re looking for an immediate solution i found that using an external usb-DAC/AMP with Analog to Digital Input conversion for your microphone will render the BEST results … onboard audio-processing circuitry is less ideal on such congested hardware like the Librem-Mini’s motherboard (too cramped inside due to so little room for a quality implementation)
see > Audiophile question
Sadly, his explanation may be the road to good enough you are looking for. IE: if it is a hardware issue, software might help mitigate it, but the hardware wont be improved.
Thanks @johndoe, that’s what I’ve been using since (I’m now pretty sure it’s a hardware fault in my Librem mini, but it was not important enough to send it back and wait for a replacement).
But now the GNU/Linux world is moving to Pipewire. Do you happen to know how to configure the same kind of noise reduction in Pipewire?
I have the same problem with 2.5mm jack in mini v2. It gives distorted sound most likely due to a hardware issue but not sure. Another issue is windows also shows the computer has a microphone connected when it isn’t.