MAX98306 Amp - Sound from one speaker

Hi there.

I’d be very grateful for some help debugging my issue here.

I’ve got a MAX98306 amp (https://shop.pimoroni.com/collections/adafruit/products/adafruit-stereo-3-7w-class-d-audio-amplifier) but I’ve noticed only one speaker is working. The fact that I’ve only just noticed is quite funny as it’s already very loud!

Anyway, the setup is as follows: 3.5mm socket is wired with Left to L+, Right to R+ and Ground to L- and R-. The L-/R- connection is also tied to the amp’s ground.

I have tested all inputs through the 3.5mm connection to the amp with a multimeter and all are correct.

I have tested connections from the board to the speakers with the multimeter.

I have tested speakers with the ohm setting on the multimeter and both show 4ohms (which is correct as I’ve got these: https://shop.pimoroni.com/products/5w-4-ohm-65mm-full-range-speaker). I have assumed that, if the speaker was broken, it would register something different on the multimeter (that, and the fact that wiring up the working speaker to the other terminal is a bit fiddly!)

Is there anything else I can do to identify the source of the problem?

I’m not sure… if I was in your shoes, I would definitely try to swap the speakers and see what happens as this would cross out a fair number of leads of your list and zone into the issue more readily.

Speaker is fine. Just tested it. So there’s something stopping any sound getting to the left output channel.

Is my wiring ok?