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Tweeters for JBL 4312A ?

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5/19/2000 9:46 PM

Tweeters for JBL 4312A ?

My buddy's got a pair of JBL 4312A "control monitors" with blown tweeters. According to the brochure, they use a model 035Ti 1" titanium dome tweeter. The tweeters have 1.5 pound magnets, so they are fairly beefy. My bud told me he had been quoted a price of $75 a piece for replacements, and this seemed a little high to me. The main problem is the mounting flange which is 5" in diameter with 4.75" between the mounting holes. This greatly limits the number of substitute drivers that can be used since almost everything I have seen has a much smaller flange.

Anyone have any ideas where I could get replacement tweeters for these puppies?

Thanks,
Mike D.

5/20/2000 2:42 AM

Mike,
Personally, I'd look around on the internet for a better price for the originals, rather than use a substitute. JBL is no slouch when it comes to making speakers, and they probably matched the characteristic of the whole speaker system to what they used for drivers. If you sub something else...it'll probably work, but you may not be happy with how they sound. Oh...and be careful with cranking high frequency distortion through the new ones...(don't make a smiley-face with the EQ).
That will blow them quicker than running a higher power CLEAN signal through them.
Brad

5/22/2000 7:05 PM

I have to agree with Brad on this one. The 4312 is a studio monitor and is designed to work best with the original components. It may not be cheap but it will be worth it to get the JBL replacements. You might look into having them repaired by an authorized JBL repair center but I think those particular tweeters are replacement only types. It would be more expensive to repair than replace. JBL is quality stuff, some of the best imo.
I own a pair of L-100's which is the home version of the 4311's. They are great sounding speakers.
RE

5/23/2000 4:55 PM
BIG Dave	I have a pair of 4311BWX. Even though they're 20 years old, everyone that hears them thinks they're awesome. Don't gamble with inferior tweeters. Get the real thing. I don't think $150/pair is high considering they're JBL's.

5/27/2000 10:42 PM

Hey, I do some side work for an authorized JBL repair shop. The dealer cost for a new #035TIa driver, without shipping or tax in
Calif. is $53.00
FWIW, replacement diaphrams
are available, JBL P/N is D8R035TIA. However, the parts & labor cost would be about the same as a new unit. Unlike most JBL PRO recones/rebuilds,
they are extremely difficult to repair (the voice coil leads are all but invisible without using a microscope, and the high magnetic flux surrounding the unit requires special non-magnetic tools.
As one who has fixed them, I would personally go for the new unit, vs. the headaches.
The previous respondents are right on about using the exact tweeter.
BTW; before buying, check the foam surrounds, if used on the woofers for rot and thinning. My 1986 4410 foam surrounds are just about played out,
and that's an expensive repair on two woofer reconing jobs!
This post is a bitlate, but...Good Luck!

5/27/2000 10:54 PM
Rich P.	OOPS! I forgot to give this JBL PRO Tech. Library info link: > http://www.jblpro.com/pages/obsolete.htm > You can get a .pdf format service document (sent as an E-mail attachment) for the the monitor(s), by E-mailing info@jblpro.com. and provide the serial no.'s. They are VERY responsive to such requests. Hasta!

5/28/2000 4:19 PM

Thanks guys,
I'm going to recommend that my buddy purchase the correct driver. Upon further examination, it appears $75 retail is not too unreasonable.

Studio monitors are one of those grey areas of life. One would think that studio monitors would be striving for the purest uncolored sound. Yet the design, driver choices and construction often seem to be on par with low-end consumer systems, rather than real hi-fi speakers. The most famous example is the Yamaha NS-10. I guess its popularity is because it represents a "lowest common denominator" and if you can get music to sound good on these, it will sound good on just about anything. It certainly is not because this is a high quality design. Even a first time DIYer could get the Dickason book and build a similar speaker that sounds MUCH better for less than half the cost. I know, I've done it.
The JBL 4312 is another example of discarding most of the principles of the Dickason book, particularly the cabinet design and the driver positioning on the front panel. They sound pretty good, though. Perhaps Dickason is a bit "anal" about things...I've built several speakers over the years using the Dicakson book as a guideline, with good results.
Yet, I have some cheap 6x9 car speakers mounted on an open baffle that sound fantastic... go figure.

Regards,
Mike D.

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