It sounds odd, but smell the bass port (the hole in the cabinet). A burnt, acrid smell indicates the speaker was pushed too hard and the electronics may be fried. 3. The "Battery Pop" & Listening Test

If you can't hook them up to an amp, bring a .

Buying used speakers is one of the best ways to get high-end audio on a budget, but it requires a "buyer beware" mindset. A speaker that looks perfect on the outside might have a blown tweeter or a deteriorating internal crossover that is invisible to the eye.