I've been seriously unimpressed with the audio quality coming from the analogue TRRS jack. After numerous tests with literally dozens of combinations of speaker/amp/power source, I cannot get rid of this seriously aggravating static hissing. At low volumes, it is especially present, such to the extent that as I turn the volume down I can hear the hiss grow more prominent linearly.
I wanted to use bluetooth audio, which doesn't suffer this static, but the bluetooth audio on a Pi3b is... Problematic. If it works for you, congrats, it doesn't for me.
Anyway, after buying some 2.4GHz wireless peripherals and a lot more testing / research, I finally discovered the source of my static issue was caused by the bluetooth.
The main indicator that tipped me off was every time I typed or moved my mouse, the static instantly got worse until I stopped moving the mouse or typing.
What seems to be happening is my wiring is acting like an antenna and I believe adding a few ferrite beads to the power wires on my amp (PAM8403, soon to be PAM8406) and the speaker wires should help reduce this issue.
My problem though is I don't know what kind of bead, there seem to be many rated for different frequencies. Which would I need? I also have a few available on 0.6M USB-A to mini USB-B cables with 24AWG wires, is there a way to tell what kind is on these cables? They don't seem to have any effect.
I searched ahead of posting but I only get 11 results, most of them duplicates.
The closest topic I found was this one:
But it wasn't any help.