4345 tweeters not working

[4345]

I have not listened to my 4345’s in quite a while. I bought some new electronics ( NAD 375BEE NAD CD PLAYER) and wanted to use them again. I noticed the speakers sounded bad. Both 2405’s were not working. I tried turning the potentiometers back and forth many times, but that did not work. What next? I will check the tweeters outside the crossovers first. If it is a crossover issue, would now be a good time to upgrade some parts? I’m not a technical expert. Any advice would be appreciated.

[Ian Mackenzie]

It might be the Lpads need cleaning or replacing

Get a technician to look at your slots if the above does not fix the issue

[4345]

Thanks. I was reading other threads on the site. Probably, should have done that before posting anyway. I am going to buy some DeOxit cleaner to spray the L-Pads. I hope this makes sense. I spent an hour reading what type of DeOxit to use and think it might be the D5 or D100, or either one. My attitude is to always try and do the simple things first.

[4345]

The L-Pads are sealed. So, spraying them with DeOxit was not possible. I did notice when I jiggled the wiring harness the slots and 2421's started working. I then decided to unplug the wires where they connect to the crossover. I really did not have to unplug them entirely, I just moved them in and out a few times. I think this made the connection better and they worked great. I then sprayed a bit of DeOxit on the connection. I waited about 12 hours and turned them on. They sound great. I am not sure I have heard them sound so good.

[Mannermusic]

The L-Pads are sealed. So, spraying them with DeOxit was not possible. I did notice when I jiggled the wiring harness the slots and 2421's started working. I then decided to unplug the wires where they connect to the crossover. I really did not have to unplug them entirely, I just moved them in and out a few times. I think this made the connection better and they worked great. I then sprayed a bit of DeOxit on the connection. I waited about 12 hours and turned them on. They sound great. I am not sure I have heard them sound so good.

Good show! As far as the L-pads are concerned, the only way I have ever been able to successfully clean those is to take them apart (bend the tabs, etc.) and apply the deoxit directly on the coils and wipers. Not exactly easy - pretty much have to pull the whole L-pad assembly out of the cabinets. I have my crossover sitting on top of the enclosures which solves that problem (DIY rig). But, connections are the bane of old electronics and you are becoming an expert (whether you like it or not). Mike

[ssrobw]

I'd really appreciate any and all advice for the same issue. I'm very lucky as I purchased my 4345s still sealed new in their boxes a few years back. I'll sometimes hear a faint bit of tweeter from the right speaker on very well recorded music, Eagles Farewell DVD and LP, but never a peep from the left and minimal from right slot. Today, after several years, I managed the nerve to Bi-amp them hoping this might bring them to life. Sadly it did not. BUT WOW! These monsters image so much better.

[Ian Mackenzie]

The poster above was good advice

If you are confident of removing the woofers you can access the crossover network

The problem could be the connectors need removing and re connection to the board due to oxidised contacts.



Go here for guidance

http://www.audioheritage.org/vbulletin/showthread.php?13930-JBL-3145-stock-crossover-A-pictorial&highlight=

http://www.audioheritage.org/vbulletin/showthread.php?13930-JBL-3145-stock-crossover-A-pictorial&p=142747&viewfull=1#post142747

[BMWCCA]

You're in Florida—it isn't the heat, it's the humidity!

Check and undo and re-do every connection you can. It is often helpful to play the system at ridiculous volume to knock an old ring-radiator loose.

And there's always the trick of using a paper-towel tube between your ear and the driver output to make sure it's working, or not.

This will also require posting the story of how you happened upon a new in-the-box pair of a monitor JBL made only about 200 of in the first place, decades ago . . .

:applaud:

[Ian Mackenzie]

It was wondering about that!