Is it okay to plug a 9v 300mA adapter to a 12vDC speakers?

Question

Is it okay to plug a 9v 300mA adapter to a 12vDC speakers?

Answer 1

Probably not.  By providing the circuits only 9 volts you are underpowering the electronics in the speakers.  This means they are trying to work (amplify sound) with less electrical power than they were designed for and can possibly overheat and burn out - especially if you run the volume up.

Answer 2

No, but I'd bet you'd do more damage to the AC adapter than the speakers, as long as you don't turn them up past the point of audible distortion.  300mA doesn't sound like enough for more than the absolute smallest set of PC or IPOD speakers, anyway.  I have a small set of Harman/Kardon computer speakers that are a single full-range driver and the AC adapter for those is 1.1A (1100mA).

I'm no definitive authority on the subject by any stretch of the imagination, but even if it did work, it would, to put it plainly, suck.