Hi VGRUBB,
I am a Magico dealer in Vancouver and have helped solved many problem just like yours from a variety of speakers. Here is what I do; 1) I gently push the unit in and feel for rubbing or scratching which obviously means it is damaged and needs replacing because this means the voice coil has been damaged or burnt out. If the unit passes this step with no scratching I move on to the next test;
2) I test for continuity with a multimeter and look for approx 4 ohms - that is good, but if it reads "infinity" the voice coil is blown or open circuit, a blown voice coil could also create a short- which would read "0" ohms. So either infinity or "0" is bad. If you do not have a multimeter, here is a simpler test - just touch the terminals with a 1.5 volt battery. You will should a pop when you touch the battery - that's a good sign. If it does not respond either the lead-in wires are broken - this is an easy fix by a speaker repair shop.
3) An alternative to step 2; I remove the unit and connect the amplifier directly to the drive unit at moderate volume. A good drive unit will play undistorted, albeit with very little bass.
Caution is advised in step 3 - do not inadvertently touch amplifier leads together - the amplifier might sustain damage - also ensure the connection is secure, then turn amp on - amplifiers do not always like being open circuit.
If I can be of more help, look me up on google - Liquidsound
