JBL TRS-225 Horn Driver Replacement

[KartRacer]

I have a JBL TRS225 speaker with no sound from the Horn. I took the woofer out to remove the driver, but the driver won't spin off by hand. I was assuming it is threaded on. I am afraid if I try to turn it any harder it will break. Is this typical? Any Ideas?

Thanks,
Scott

[J M Fahey]

*Maybe* it's threaded, maybe it has four (or 2) small screws, if plastic it might be glued , meant to replaced in full with horn and all (wouldn't surprise me in these "replace/do _not_repair" days).
Did you ask JBL?
Post a few pictures which might clear the issue.

[KartRacer]

Here is a couple of pics. Hope they upload ok. Looks to me like it should unscrew. I am thinking using a pair or channel lock pliers on it. Any other thoughts?

Scott

[J M Fahey]

Channel pliers belong into your gas or water pipe toolbox.
*Most* drivers (all Pro ones) are not screwed to the horns but have a flat frontplate bolted with 2 , 3 or 4 screws to the horn flat backplate or, worst case, a horn adapter.
In this case I have indicated them; their heads usually are Allen or Hex; but JBL might have decided to become creative with this.
(Not with the driver, which looks more Chinese than the Golden Dragon Teahouse in San Francisco).
You unscrew it, carefully lift it from the horn/adapter, you'll find a cardboard gasket and a replaceable piece of PCB material (Phenolic or epoxy) with the diaphragm, voice coil and terminals mounted on it as a plug-in unit.
You can order a replacement assembly from JBL; there might even exist aftermarket ones if the horn is popular.
Of course, I guess you already measured the Voice Coil continuity and declared it dead.
You reassemble it carefully retracing your steps backward.

Good luck.

[Mark Black]

That driver is indeed a screw-on. Sometimes they use a little adhesive on the threads to keep it from loosening (sometimes a little too much - yours might be in this category).

JBL considers this to be an entire unit replacement and does not sell a diaphragm (only a complete driver), but there are a few folks on Ebay who do. Just do a search for JBL 2412H. The driver does not have very stellar frequency response (rolls off heavily at about 12 or 13KHz), so pretty much any screw-in driver of the same (nominal 8 ohm) impedance will probably do as well.

Some buddies and I think this driver looks suspiciously like a Foster, possibly OEM'd for JBL. Wouldn't be the first time - I think the woofers in that cab are made for JBL (and to their spec) by Eminence. Those are also entire unit replace types (no available cone kit) as per JBL.

[J M Fahey]

Well, I guess we are both right.
I suggested pulling screws holding the driver unit itself from the silver "driver to horn adapter", which very probably *is* screwed into the horn, although it wouldn't surprise me at all if they saved 0.05 cents from manufacturing cost and just epoxied said silver (aluminum) adapter into the black horn throat, no threads involved.
If they exist and they used a drop of Crazy Glue or similar, you may heat somewhat the neck with 15 seconds of blowtorch (no kidding) or 1 to 2 minutes of electric heat gun om max.
That, supposing the horn is metallic !!!!
In any case, you will still need to open the driver to be able to replace the diaphragm.
If it's a Fostex (very good for the price) you'll probably find a replacement diaohragm assembly .
As Mark Black hinted (and I fully agree), maybe some bright kids already figured this and are selling working replacement diaphragms.
Foster/Fostex drivers? Eminence woofers? Nothing against that, *I* would use the same, but .... shame on you "whoever_owns_the_JBL_brand_today"
Well, now I know why everybody and his brother owns at least a couple JBL boxes these days.
I remember my amazement when I repaired a couple blown "made in USA" Yamaha cabinets some 10/15 years ago, and they had Eminence stamped basket woofers with roundwire voice coils and not the sleek Yamaha cast frame ones, with edgewound aluminum voice coils I expected.
Drivers were excellent Yamahas though, they had a lot of sparkle.
Oh well.
Anybody wants to buy a Tadjikistan made Ferrari?

[Enzo]

When I have a screw on driver that I can't turn by hand, I use a strap wrench. You can find them at any hardware store or Sears or Harbor freight. Basically a handle and a strap. Strap is rubber or fabric. Works on oil filters in your car too.

Search results for: 'strap wrench'