Sonos Play:1 mid-woofer vibration noise.

I recently picked up a pair of Sonos Play:1s from OfferUp and wouldn't you know it? Both seem to be blown.

Let me explain, whenever I play a song with ANY bass to speak of I get this terrible noise like you would hear if you put a vacuum hose up to a ribbon while holding it. It makes a sort of distinct vibrating sound.

Naturally, since these have no warranty to speak of, I opened them both up. To my surprise there appears to be no superficial issues with either of the mid woofers. I went ahead and tested each of them outside of their cabinets and to my surprise they sound exactly as expected (really good). This made me curious. So I went ahead and put my finger over the hole in the back on the speaker (picture below)

When I placed my finger over this hole I noticed that awful vibration noise immediately! This made me wonder if the speaker was having issues with compression. So then I went ahead and put the speaker back into the cabinet but didn't put the back cover on the cabinet. The sound (likely due to lack of compression) was slightly weaker than I would expect for a Sonos Play:1 but the vibration noise wasn't present. Shortly after, I placed the back cover over the back of the cabinet and pressed firmly against it and the same vibration noise was back again.

I know several people have had a very similar issue with their Sonos products. I assume this is an issue with the mid woofer and not due to the compression within the cabinet.

All of that to ask, does anyone know why the mid woofer can't handle the cabinet's compression? Do I need to just replace them or can I fix the issue?

Thanks!