I managed to remove the grill from the speaker behind the seat and, I must admit that I have never before seen a speaker situated in that manor.

I did not see that the cones were deteriorated. I was under the impression that when a speaker blows, it will make an annoying sound. I have never heard that a blown speaker will emit no sound.

My friend said that when he heard my stereo last Summer, that he heard some bass and that maybe it was coming from the other speakers? If I can find his number, I will call the previous owner and ask if he knew of the subs not working.