Replacing diaphrams?

[BigT]

I asked a while ago how hard it was to recone a woofer. The responses I got convinced me to leave that task to experts. Now - how difficult is it to replace the diaphram in a horn tweeter, specifically the JBL 2404h? I suspect it's much easier than replacing a woofer cone. Are those diaphrams sold on Ebay as good as JBL originals? Are there others available that might be preferrable?

Thanks!

[johnaec]

The biggest thing to watch out for is wrinkling the diaphragm from twisting the phase plug when you screw it all back together. Also, note that the original 2404H uses the D16R2405 diaphragm, while the 2404H-1, (used mainly in JBL sound reinforcement cabinets), use the heavier duty D16R2402 diaphragm. The 2402 dia. does not have as extended HF response as the 2405 dia. You can put the 2405 dia in either way - that's the only difference between the H and the H1, (and the foilcal).

Also, most people that have tried them have found the aftermarket diaphragms lacking in sound quality, though what "sound quality" might mean could be different things to different people. I had a 2447J driver with an aftermarket dia. in it, and when we actually ran tests comparing it to a factory one, the factory one had far better HF response.

John

[clmrt]

I did it once and only once, and was stupid enough to post a pictoral "how to" here, where everyone else probably got a good laugh.



Thanks again for the 'phram, Z.

[BigT]

Could someone go through the procedure to replacing the diaphram in a 2404h tweeter? I don't need to do this, but knowing the procedure would help me decide whether to bid on or buy a 2404h that needed a diaphram.

[clmrt]

Found it -

http://audioheritage.org/vbulletin/s...ead.php?t=6532

[clubman]

I would stick to factory JBL diaphrams, the aftermarket ones don't hold up as well in my opinion. I have replaced one jbl diaphram in 3 years at a nightclub install. 1 out of 8, I tried one aftermarket that I picked up localy and it only lasted about 6 months. But you may have better luck with the aftermarkets given your using it in a home setup.

[1audiohack]

I did two of my own 2404's and did not find it difficult in the least. That said, I "mechanic / machine" for a living so this type of project is the norm for me.

I don't have experience with aftermarket parts, I do know the 2402 diaphragms fall like a rock at upstairs, not what you want for home. I have two in the JBL boxes I'll never use. Get 2405's for sure.

A frequency generator to "dyno" it when your done is a nice plus.

The "How Hard to Recone a Woofer" was a fun topic. I did three of my 2123's after watching the professor do the first one, and even the glue line looked good. My TEF verified the results. A very satisfying experience!

If you still want to do that, save some time, spend some money, and pay a pro for an education.

Explore and enjoy.

[Fangio]

You definitely want to have a tone generator handy, to listen for anomalies once the diaphram screws are tied up again. Music alone won't suffice for a true test.

Here's another worth reading

http://audioheritage.org/vbulletin/s...ad.php?t=10625