If what you are saying is that it burns out the speaker then if you did a
led mod you have a short in your mod that is drawing to much current
through the speaker and burning it out.
Did you add leds ? How many ?
If you hook to the wrong side of the speaker and the leds get their power
through the speakers you can burn the wiring in the speaker out.
If you modded with leds disconnect the one side to the speaker and
test to see if it runs ok that way.