Late 70
A friend of mine did some DJing in the late 1970s and he was in possession of a rather impressive power amp. I possessed some rather inferior domestic lo-fi speakers.
In the interests of science we sacrificed the speakers by turning up the amp power until the speaker coil burned out.
I'd have to agree that clipping is more dangerous to speakers because they made a hell of a lot of noise before melting. As in 'I CAN'T BELIEVE HOW LOUD THESE SPEAKERS ARE!' 'WHAT DID YOU SAY?'