Audio Systems: Back Speakers Only Cut in At High Volume, punch xlc, honda prelude

Question
Dear Cleggsan
The back two speakers in my 2001 Honda Prelude only *try* to kick in at high volume. By *try*, I mean that they will go on for a short seconds periodically. I am not aware of everything that has been done to this car audio system, but here is some information I got...
The cd player is a "Clarion PRX6675z"
There are 2 10 inch "Punch XLC" subs in the trunk.
There is a amp that says "power 200 a1" on it (attached to the back of the sub box)
And I have no idea if the speakers are stock or have been upgraded?

One sub doesn't work at all, and the one that does work sounds horrible. The cd player volume range is from 0-32 and the back speakers only cut in randomly from about 28-32 (from what I can notice) I realize that I have a disaster on my hands, but I was wondering if there is anything I can do to at least get those back speakers working so I can improve the sound in the back of the car??? Your help is greatly appreciated! Thank you!  

Answer
What you have described is clearly, from my personal experience, failure of the voice coils in the speakers. I am quite certain the speakers will need to be replaced. If you have a vom and know how to use it they are easily tested.

If not, let me know your proclivity or pulling one of them out and I can tell you how to test it by using a D size battery across the terminals.

Door mounted and back deck mounted speakers are cheaper to replace, but the subs can be repaired at a good speaker repair shop - if you can find one.

Hope this helps.

Cleggsan