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hifigi
09-21-2006, 10:02 AM
I just bought a pair of c50 S7R. Cabinets are near mint (teak) Grills are perfect.

Hooked hooked up for a few minutes and they played fine. Turned the system off and went to bed. Got up this morning and the woofers are frozen.

There was no amp thump when I shut it down. and the speakers were not moved. I am at a loss.

At any rate can someone recommend a GOOD rebuilder. I would like these to sound and LOOK like they did now (white surrounds)

edgewound
09-21-2006, 10:20 AM
I just bought a pair of c50 S7R. Cabinets are near mint (teak) Grills are perfect.

Hooked hooked up for a few minutes and they played fine. Turned the system off and went to bed. Got up this morning and the woofers are frozen.

There was no amp thump when I shut it down. and the speakers were not moved. I am at a loss.

At any rate can someone recommend a GOOD rebuilder. I would like these to sound and LOOK like they did now (white surrounds)

White Lansalloy surrounds haven't been made in about 40 years.

They would get reconed with a factory JBL 2215 recone kit with a foam surround.

Thom
09-21-2006, 04:15 PM
I'd make real sure that something didn't fry them over night as that sounds very suspicious. If your power amp were to leak dc and you are using a typical passive crossover, it would protect every thing except the woofer. I'm not trying to diagnose anything long distance, and I'm not making assumptions about your technical skills,there isn,t enough information to do that, but if by frozen you mean you can't move them by hand and they played "perfect" the night before that is very strange. Does every thing buy the woofers play? You didn't specificaly say both channels but your wording pretty much indicates so. A burnt coil or a slipped magnet assy are the only things I can think of that will freeze one up. A spider that comes loose will make it un playable but it won't lock it up. Were they mine, I'd not gamble a second set of expensive woofers without at least a once over. Good luck.

Zilch
09-21-2006, 06:08 PM
At any rate can someone recommend a GOOD rebuilder. I would like these to sound and LOOK like they did now (white surrounds)Go to "User CP," and enable location display in your profile so we can make a recommendation....

Surrounds are shot now, right?

What does "frozen" mean?

scott fitlin
09-21-2006, 07:12 PM
Go to "User CP," and enable location display in your profile so we can make a recommendation....

Surrounds are shot now, right?

What does "frozen" mean?It means the woofer cones dont move, they are frozen in place.

The only things I know that causes this, is SEVERE overdrive, or DC.

If the amp discharged DC during turnoff, you wouldnt hear it, the only thing you would find is the damage, which, he found.

Do you smell a burnt smell from the woofers? If you do, the voice coils are broiled to black crisps.

mech986
09-21-2006, 07:27 PM
Are you sure that the woofers are "frozen" or the surrounds are so stiff that they won't allow any significant woofer motion when you check them by hand motioin?

Even with really stiff surrounds, the woofers will still make some upper midrange sound. If you tried to play them with deep base and pushed them, the surrounds would likely break, hence the broken surround question above.

it is possible you drove the system in trying to get output with enough power to overheat the voice coil causing an open circuit or short, then the speaker won't work but will seem frozen because of the stiff surrounds.

Have you checked on the speakers by trying to drive them a little with another amp or pulled the drivers and checked the DC resistence of the voice coil?

Please let us know.

Regards,

Bart