L46 driver

[rockecat]

Hey Guy's a little help, last night while spinning some vinyl the woofer on one of the L46's started distorting really bad. I pulled the woofer out and it looks fine. I appreciate the help as always.

[Zilch]

Swap it with the other one, and see (hear) what happens....

[rockecat]

Swap it with the other one, and see (hear) what happens....


10-4, I swapped my L50 over to that channel and had no problem.

[rockecat]

OK I swapped the woofers and it sounds normal, so something is definitely wrong with the driver.:(

[mech986]

Hi, mark the woofer so that you know how the frame was oriented when originally mounted. Then rotate the frame 180 degrees so that top is now bottom. Then retry the woofer, gently the firmly and see if the distortion is still there. THis would test for spider sag in a vertical position.

If not ok, then do the following.

Inspect the suspect woofer and see if there is any damage to the surrounds at all. If it looks ok, place it on its magnet and press lightly down and pull lightly up on the cone to see if there is any evidence of voice coil scrape in either direction and at the extremes of travel. This would check (roughly for any shape distortion in the voice coil like from overheating.

If that does not show you anything, then put it on the other good channel and try again.

Here's the tech sheet:

http://manuals.harman.com/JBL/HOM/Technical%20Sheet/L46%20Sigma%20ts.pdf

Could it be that the crossover inductor or capacitors have gone kaput?

Regards,

Bart

[pelly3s]

also check the tinsels one could be going bad and giving you all sorts of problems

[rockecat]

Ok , I tried everything and the problem still persist. I feel no drag at all and the surround is only a year old and it distorts the same in both speakers. :banghead:

[rockecat]

Anybody have a recommendation for a repair facility in the St,Louis or
Kansas city area.

[jay]

You can eliminate doubts about the crossover network by moving the known good woofer into the 'bad' cabinet. If it works normally, then it has to be the woofer.

At that point, suspect the voice coil wires came unglued, etc, etc. :(

[rockecat]

Yep ,already tried it the bad woofer is bad in either cabinet, the driver appears fine and I can detect no rubbing and the wires appear fine.:(

[pelly3s]

if you can put a very low signal into it just enough to get sound to come out and move the tinsle wires around and see if something happens. also check for a loose dust cap or if the cone and coil joint is loose. another thing inspect the edge of the spider to see if that is lifting. And what is the DCR of the coil in that driver

[rockecat]

if you can put a very low signal into it just enough to get sound to come out and move the tinsle wires around and see if something happens. also check for a loose dust cap or if the cone and coil joint is loose. another thing inspect the edge of the spider to see if that is lifting. And what is the DCR of the coil in that driver

Ok I will give that a try. The Dcr is 5 Ohm min 6 max

[rockecat]

if you can put a very low signal into it just enough to get sound to come out and move the tinsel wires around and see if something happens. also check for a loose dust cap or if the cone and coil joint is loose. another thing inspect the edge of the spider to see if that is lifting. And what is the DCR of the coil in that driver

Good call, when I ran a low signal through I can actually make it work or not work by moving the wires or whole cone. Should I unsolder the wires and redo next. I really appreciate the help, I can build a superbike and understand the process of elimination. I have never worked on audio equipment before and have learned the hard way to seek out advice in unfamiliar territory.:blink:

[pelly3s]

if the problem occurs more towards the cone then most reconers can repair it without reconing the speaker. if it is at the terminals then resolder them and see if it helps. if you want to try to fix them yourself try applying solder to the tinsel wire at the cone and see if them helps uses enough heat to get the solder to flow through the lead just dont burn the cone.

[Don C]

You mentioned that you were playing vinyl when the problem showed up. Does the speaker have problems with playing CDs as well? Did you try turning on a subsonic filter?

[rockecat]

You mentioned that you were playing vinyl when the problem showed up. Does the speaker have problems with playing CDs as well? Did you try turning on a subsonic filter?

Don, I did not try a Cd but it does it using the FM tuner also.

[rockecat]

I would like to thank Steve Gonzales for his generosity in providing me with another driver I will make a contribution to the website in his honor. Thanks again Steve :applaud: :applaud: :applaud: