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View Full Version : When it just sounds plain bad!


Robh3606
09-11-2004, 08:01 PM
I got a pair of blonde L20T3 on E-Bay. They were in good shape at a great price $45 BIN I hook them up and :no: :barf:

They sounded awful!! I coudn't figure it out no highs all congested muted just awful!!! First I thought the tweeters were fried but they were still there. Could not figure it out so I think maybe the crossovers are screwed up?? I open them up and there are 70 volt transformers in them. Took the transformers out and they are fine! No wonder the guy dumped them!


Rob:)
scott fitlin
09-11-2004, 08:22 PM
I just dont understand why anyone would have put 70v transformers in those!
Figge
09-12-2004, 04:20 AM
do u have a pic of the transformer?

this could be a bose design!
Robh3606
09-12-2004, 06:15 AM
You can see the tranformer inside. They must have been in a bar the grills smell a bit like smoke. Glad they work now though!
boputnam
09-12-2004, 06:48 AM
Originally posted by scott fitlin
I just dont understand why anyone would have put 70v transformers in those! Those must have been intended for a 70 volt distributed system. That speaker would likely have sounded fine - "as was" - if connected to a 70 v signal. The 70 volt transformer took the 70 v signal and converted it (back to) a 8 ohm signal. The cabinet's size would make it a great candidate for a distributed application.

70 volt distibution is common here; in Europe they favour (sic...) 100 volt systems.
GordonW
09-12-2004, 08:37 PM
Back in the day, 70V was a factory option available on most of the L-series stuff in the 1980s. Dunno if this was a factory 70V unit or not, but if I had to guess, I'd say it probably was.

Regards,
Gordon.
Robh3606
09-13-2004, 04:49 AM
"Back in the day, 70V was a factory option available on most of the L-series stuff in the 1980s. Dunno if this was a factory 70V unit or not, but if I had to guess, I'd say it probably was."


Didn't know that. These were done by the owner. They were in OK but I can't believe factory would be all tape and splice.

Rob:)
GordonW
09-13-2004, 07:40 AM
OK, wow... I couldn't get the picture to download completely before. Even without considering the tape job, that's definitely not a factory JBL 70V transformer. Too small...

But yeah... there was an option to order most of the (at least the smaller ones) JBL cabinets with 70V transformers, in the 1980s. This is how many of the "consumer-type-looking" JBL speakers you used to see in bars, record stores, etc. used to be hooked up.