Purchased a pair of Sierra-1 speakers last month and they had been working great.

Woke up yesterday and one of them just stopped producing any sound. Confirmed that it is in fact the one speaker and not another part of the larger setup. Switching the L/R speakers confirmed that.

I can't see any physical issues, but honestly wouldn't expect there to be as it's just my wife and I without kids and haven't touched the speakers since setup a few weeks ago. Spent about 30min originally thinking it had to be my older Denon AVR-S710W somehow (settings changed or an issue), but nope - it's the one speaker.