What's Wrong with 4343 Woofer?

[pyonc]

Hi, all,

Please give me your diagnosis and solution. And this is what happened:

I was trying to test vintage Crown VFX-2 crossover for 4343 this afternoon.
I hooked all the input and interconnect cables, only turning on the loss pass Xover switch, with the high-pass swtich off. When I did so, I heard some sort of strange
audible noise coming from the woofer (2231A) of the right speaker initially, and it disappeared. I didn't hear that from the left woofer.
When I did it the second time, I heard the same. Now the problem was since that happened, I could not hear any bass from that right woofer. What's wrong here? Any way to fix it by myself? Please help me out!!! At this point I just regret toying with this old Crown X-over, not knowing fully about its function...

[hjames]

What do you get when you remove the Crown crossover from your system and hook everything back up normally?

Hi, all,

Please give me your diagnosis and solution. And this is what happened:

I was trying to test vintage Crown VFX-2 crossover for 4343 this afternoon.
I hooked all the input and interconnect cables, only turning on the loss pass Xover switch, with the high-pass swtich off. When I did so, I heard some sort of strange
audible noise coming from the woofer (2231A) of the right speaker initially, and it disappeared. I didn't hear that from the left woofer.
When I did it the second time, I heard the same. Now the problem was since that happened, I could not hear any bass from that right woofer. What's wrong here? Any way to fix it by myself? Please help me out!!! At this point I just regret toying with this old Crown X-over, not knowing fully about its function...

[pyonc]

What do you get when you remove the Crown crossover from your system and hook everything back up normally?

Well, I turned back to my existing biamp set-up with JBL M552 X-over, and I could hear no bass from the woofer in question. And I tried single amp mode this time from biamping, and the outcome was the same. Any possibility that the woofer's been damaged in one way or another, or any other problem?

[grumpy]

Biamp switch on 4343? tried moving that back and forth a bit (scrubbing the switch
contacts in doing so)?

[PaulB]

My babies... my poor poor babies...

Do you know how to use an ohmmeter? I've got a bad feeling about this...

[pyonc]

My babies... my poor poor babies...

Do you know how to use an ohmmeter? I've got a bad feeling about this...

Dear Paul,

Glad to hear from you. Ohmmeter? What's that?
I just keep my fingers crossed no damage has been done to the woofer.

[pyonc]

Biamp switch on 4343? tried moving that back and forth a bit (scrubbing the switch
contacts in doing so)?

Yea, it doesn't help either.
Do you see any possibility some sort of damage being done to the woofer with this vintage Crown X-over?

[grumpy]

sure. If it put out DC and it wasn't blocked or limited by the amp fast enough...
poof. Could still be something else, like a loose contact, but if they were mine
the woofer would be coming out for testing (such as testing with an ohm meter
to measure resistance... see if the coil has opened/burnt or shorted). Crossing fingers
for you...

[PaulB]

An ohmeter measures resistance (continuity of the voice coil in this case). I hate to say it but my guess is that it's fried.

If you want me to walk you through how to test this, shoot me an email. I hope I'm wrong but sure sounds like it to me. If you tested it in normal mode and that's consistently the only driver not working (just for fun, did you try switching amp channels?), then the most likely explanation is that the Xover was faulty and burned out the woofer voice coil.

[opimax]

Chang,

I can be available Mon night and I have a meter

Mark

[hjames]

An ohmeter measures resistance (continuity of the voice coil in this case). I hate to say it but my guess is that it's fried.

If you want me to walk you through how to test this, shoot me an email. I hope I'm wrong but sure sounds like it to me. If you tested it in normal mode and that's consistently the only driver not working (just for fun, did you try switching amp channels?), then the most likely explanation is that the Xover was faulty and burned out the woofer voice coil.

If his system is setup for Biamp, he should have just the Woofer leads coming out of the back of the system somewhere, right?

Unless the biamp switch has failed and completely removed the woofer out of the circuit somehow, can't he use a regular 1 1/2 volt battery (a single AAA, AA, C or D-cell) and, with a short piece of speaker wire, briefly connect the battery across the woofer leads and get a thump to verify the woofer is still useful??

I mean just the basic go - no go test?

[grumpy]

yep... in fact, it shouldn't really matter if it's in biamp mode or not.

I -did- say if they were mine ... Then again, I have no compunction about ripping
things (like speakers) completely apart for grins; and these were made to be serviceable.

[pyonc]

Chang,

I can be available Mon night and I have a meter

Mark

Hi, Mark,

Looks like the voice coil has been burnt, according to our forum members.

What time are you available Mon. night? Just let me know.

Thanks, my friend.

[pyonc]

sure. If it put out DC and it wasn't blocked or limited by the amp fast enough...
poof. Could still be something else, like a loose contact, but if they were mine
the woofer would be coming out for testing (such as testing with an ohm meter
to measure resistance... see if the coil has opened/burnt or shorted). Crossing fingers
for you...

I'm afraid the cause of the malfunctioning belongs to one of the three causes you've just mentioned. I played Test CD to check the bass of the woofer in question, but I heard no sound or noticed no treble, starting with 80Hz warble and up, compared with the other woofer that works perfectly okay. Now, how can I have it fixed? Send it to a JBL dealer? Just this one in trouble, or both? Thanks always.

[PaulB]

If his system is setup for Biamp, he should have just the Woofer leads coming out of the back of the system somewhere, right?

Unless the biamp switch has failed and completely removed the woofer out of the circuit somehow, can't he use a regular 1 1/2 volt battery (a single AAA, AA, C or D-cell) and, with a short piece of speaker wire, briefly connect the battery across the woofer leads and get a thump to verify the woofer is still useful??

I mean just the basic go - no go test?

He could use a battery Heather, I prefer an ohmmeter because it limits the current although a small battery isn't likely to do any harm. But a battery won't tell him if it's shorted or open (open being much more likely). I'd pull the woofer (4 screws IIRC) so that you can double check the remote possibility of a loosened connector. In any event methinks it's a toasted woofer