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View Full Version : JBL SVA1800 tweeter inop/disassembly help...



Cincy_Ron
04-01-2011, 06:05 PM
Howdy folks, new user to the forum. I've got a set of JBL SVA 1800's that I really like but for some reason the tweeter on my right speaker is tango uniform. It's been like this for a year or more, and even though I've got a high frequency hearing loss in my left ear which kind of evens things out for me naturally, I would like to fix whatever is wrong. :)

First, before I tear something up, is there a trick to getting this thing out of the cabinet? There are 4 screws that look like they are holding the tweeter surround to the cabinet which I have removed, but I just can't seem to get the assembly to budge. Is it glued in addition to the screws?

Once I figure out how to get the tweeter out what I'll probably do is swap it with the good speaker and make sure it not something with the crossover and go from there as far as finding a replacement if I need to.

I've googled and searched the forums here but can't seem to find any info on how to proceed...

JBL 4645
04-01-2011, 07:35 PM
I wouldn’t know I never owned SVA1800 I would guess its got a compression driver attached to horn assembly. The diaphragm would be glued to the magnet structure first un-solder the wires and it needs to be peeled off! A new diaphragm needs to be replaced by gluing it down and re-soldering the wires and testing it.

I’d say possibly the voice coil was burnt out? Then again maybe it’s a lose wire? Or maybe the crossover has gone queer?

One or more of the other members that have JBL SVA would know how to tackle the issue. As where to get hold of spare parts.

If you have to boast the high frequencies to compensate for some left ear frequency loss I would strongly recommend you use an independent crossover electronic with audio limiting to protect the high level peaks from further voice coil burn outs! That is what happened a peak frequency came along and you played it for too long where the strain built up and fried the voice coil. Does it have strange smell?

Don C
04-02-2011, 11:11 AM
After the screws are out, it's not unusual to still have trouble because the gaskets tend to stick. I usually put a screwdriver in one of the mounting holes and lift from there. You might try removing a woofer to get access from behind. But the woofer is often stuck as well. You will eventually get it apart. Here's a link to the tech sheet, in case that helps.
http://www.jbl.com/resources/Brands/jbl/Products/ProductRelatedDocuments/en-US/technicalsheet/sva1800%20ts.pdf

Cincy_Ron
04-02-2011, 01:16 PM
Excellent. Thanks Don, that tech manual really helps me out. I've got a 2" plastic putty knife I'm going to try working around the horn and gasket and if that doesn't work I'll see if I can get a woofer out.

JBL 4645, I'll give it the sniff test one I get out, thanks for the reply and info!

Titanium Dome
04-05-2011, 10:03 PM
If you haven't done it already, do not try to remove the horn enclosure. It's held in place by eight screws, not by four. Two screws are underneath each of the two fake woodgrain panels. More...

Titanium Dome
04-05-2011, 10:20 PM
If you remove the fake woodgrain panels, you'll ruin them. They are no longer available from JBL. If you can live with just the raw plastic with the mounting holes and screws showing, then you still risk cracking the plastic housing trying to pry it off.

The safest method is to remove one of the 8" drivers and remove the HF driver from behind the horn. Yes, it's working blind, though if you remove both 8" drivers you can get a mirror in there to see what you're doing. I just do it by feel. You'll need one of those off-set screwdrivers to get in the cramped space.

If you've already taken off the horn successfully, replaced the driver, and replaced the horn, never mind :)

Cincy_Ron
04-06-2011, 09:47 PM
Titanium, thanks for the info! I haven't gotten around to this yet so no damage done! BTW, you had posted some part numbers about 3 years ago that I came across while searching google. Do you have a recommendation on a replacement driver?

Thanks!