Quote Originally Posted by nino View Post
Hello everyone,

I was hoping someone could shed some light on what just happened to my beloved set of mission 737Rs. I have them hooked up in my main system an apt holman pre/power amp and a kenwood record player. I often stream music also. I noticed the sound coming from the right speaker was a little off to start( started about 10 days ago) but would become normal after the first song was played. I figured since it was older equipment it was somewhat normal. Today I hooked it up to my Ps audio 5.5 pre amp/ ps audio cx200 power amp and played it with the same record player and streaming device. After the first side of the record I noticed that the woofer was no longer working. The woofer is stiff and will not move.

I understand the woofer is fried, but why? To trouble shoot I had switched the speakers left and right hook up on the amp. The left speaker worked perfect with both sides. Yes I understand the speakers are about 30 years old.

Thoughts? suggestions? Should I go get my amplifers checked out? Would rather not fry another set of speakers.

Cheers,
Nik
A stiff woofer, as you have described, happens with the voice coil burns and fuses to the pole piece or magnetic gap. Typical cause for this is a DC offset in your amp (amp needs to be repaired) or pushing the woofer to hard with very deep bass and too much power. Being that the woofer is at least 30 years old, it is also possible that the voice coil adhesive has broken down causing the coil to unwind and then short.

First step is to check out your amp - if it is bad, it will continue to damage speakers.