I tried the hardon kardon speakers from another A300 and not the regular ones and also they got blown.
This happens when I'm playing a music at 100% volume (with default settings without any boost setting turned on) I replaced it with another pair of speakers for the A300 and this time it happened the same with the right speaker. I have a Toshiba A300 that had suddenly had problems with the left side of the speakers it started to fade away and distort until it became blown.