Salvatore wrote:
Would like to replace the 12" woofers in these and wondered if anyone knew
of a decent quality similar spec DVC woofer for them.

I owned a pair of QLS's for about 4 years in the late 80's.
One of the things that made the QLS unique was that it used a
"Watkins woofer". My understanding is that the Watkins woofer
had 2 voice coils, each with a different impedance. To extend
the bass response, a special crossover shifted frequencies
near the resonance point of the first coil over to the second
coil, which had a different impedance & lower resonance frequency.

Every dual voice coil woofer I've seen for sale in the last 15
years has had 2 coils with the SAME impedance. I haven't looked
around, but it may be hard (if not impossible) to find a new
woofer with the special impedance specs of the Watkins woofer
used in the QLS. I know that's not very helpful, but I'm
just saying an off_the_shelf woofer might not make a suitable
replacement. It would be better to either repair the one
you have, or try to find an exact replacement.

Chip
San Francisco, CA