I’d never had my hi-fi (well medium-fi, a 90s Kenwood amp with 70W a channel) flat out till junior listened to some techno or metal while I was out. On return one speaker had lost its bass. The driver showed 8ohms so he hadn’t burned out the coil, I took it back to the shop and got a call not longer after “it’s fixed now and sounds fine, the speaker cone had gone beyond its normal range and got stuck”.
“It wasn’t that loud” protested junior. Compared with band practice (150W guitar amp, 300W bass amp, keyboads and voice through a 400W PA and drum kit – all in a small room) I’m sure it wasn’t that loud.