Adjusting audio balance (left/right) and delay (left/right)

I would like to reduce volume, as well as add a very slight delay, on one side only. How could I do it? Using a Raspberry Pi 3 v2 and it’s 3.5mm audio jack. Thanks.

You should be able to adjust volume with alsamixer.

sudo apt-get update && sudo apt-get install alsa-utils

If the volume control is stereo you will see two numbers under the graphic which can be individually changed with the W, R, Z and C keys.

Adding a delay to one channel is not easy but you might be able to do it with some ALSA conf files.

okay, I did it, but amixer says playback channels are mono
alsamixer says “headphone”
sound is playing in stereo, but I can’t control each channel separately

I was afraid of that. I don’t have a Pi fired up on OSMC to check atm.