2404 Questions

[kegger]

Recently acquired a pair of 4628B's with 2225's, 2118's and the 2404's.

All the drivers are good and I've been playing around with a system utilizing those
drivers, except one 2404 has an aftermarket diaphragm that is bad, ripped/torn an
the other sounds fine to me (nothing to judge it against) but I took it apart to see
what was in it, looks like a factory 2402? You can kinda see in the pic, that green
circle there is a "dent" in the diaphragm, not ripped or cracked but not nice.

So I'm wondering what the preferred option would be, get another 2402, a pair of
the 2405's with the higher top end? I'll be utilizing them in a 3-way crossing at 4k
or higher, also money is pretty tight these days, so I'm just weighing the odds.

(I use low power tube amps, generally 20watts or less if it makes a difference)

Anyone change out a 2402 for 2405 or other?

Thanks,
Paul

[Allanvh5150]

Hi Kegger,

When the 2404 was used in this system and the 4612, JBL ran it with the lower crossover point of 3Khz. To acheive this JBL used the 2402 diaphragm. The diaphragm should be replaced with the original 2402 otherwise if you use the 2405 you will pop it in no time.

[kegger]

I am building a complete (new) system with these drivers an will cross no lower
then 4k or higher, and use low power amps, is the 2402 still the recomendation?

[Allanvh5150]

The minimum recomended crossover for the 2402 is 2.5khz, the 2404 is 3khz but I think that is with the 2402 diaphragm. Anyone can correct me if I am wrong. The minimum for the 2405 is 7Khz. I wouldnt cross the 2404/05 any lower than 10Khz. The diaphragm in the 2402 was a lot beefier but I would probably go with 7-10K for those as well. Obviously using a 2118 you will need to crossover at around 3khz. If so I would go with the 2404 with the 2402 diaphragm. What will you use be?

[kegger]

Thanks for your thoughts, Allan it is?

Will surely take your info into consideration. (2402 sounds like the plan)

Using the 2118 I'm just running a cap in series 1st order on the high pass side
and letting it drift off on it's own then passing it to the 2404, so there is a bit
of gap between where the 2118 starts to roll off an the 2404 takes over in the
4 - 5k range with a second order on it. And I'm building this particular setup for
a low power SET amp in particular, really less then 10 watts most of the time.

I do understand and appreciate where your coming from, I have the combo in
use at the moment with just 1 speaker running, it sounds quite nice..

Thanks,
Paul

[Zilch]

2404H with the 2402 diaphragm was designated 2404H-1.

The JBL recommended replacement diaphragm, even in these instances, is D16R2405, here, for example:

http://www.jblproservice.com/pdf/Cab...ries/4612B.pdf

http://www.jblproservice.com/pdf/Cab...ries/4628B.pdf

The recommended crossover frequency for the stock 2404H using the 2405 diaphragm is 3 kHz, 12 dB/octave or higher:

http://www.jblpro.com/pages/pub/components/2404.pdf

We measured the performance of the two diaphragm types in 2404H in the "Ring Radiator Comparisons" thread, and the difference in VHF extension between these variants is readily apparent.

I'm suggesting that Kegger should replace his with the 2405 diaphragms....

[Allanvh5150]

Interesting Zilch. I have never spotted the replacement diaphragm type on these sheets before. Good to know. Any ideas why they put the 2402 'phragm in there?

[Zilch]

Playing "Safe," perhaps, until proven otherwise. Those products didn't require VHF extension.

Materials may have changed in the interim, perhaps.... :dont-know

[Allanvh5150]

So has anyone tested a 2402 with a 2405 phragm in it?

[Zilch]

As I recall, we had zero interest in that combination at the time; we were doin' cateyes, primarily.

[That'd be Toddalin territory.... ]

[SMKSoundPro]

I am using 2402 bullets with 2405 aftermarket phragms in the rig I built for the larger ballroom. I did not have enough 2402 phagms, but had plenty of the aftermarket ones form Sound Speaker Repair in Tuscon, AZ. I am running the four bullets from 8Khz up to daylight using an electronic crossover and protection caps off of a Crown Macro 600 amp.

I have already popped one of the phragms and will be installing the right D8R075 phragms in all four bullets.

What else do you want to know?

scotty.

[Allanvh5150]

Maybe the fact that it was aftermarket may have something to do with it.....

[kegger]

OK well that was a big twist an bunch of info compaired to yesterday, huummm.......

Good stuff guy's!

[kegger]

For the time being (sacrelidge I know) I have subbed the 2404 with an AUDAX
high sensitivity dome tweet, definatly got more sparkle then the 2404 with the
2402 diaphragm in it.

Until I can come up with the cash to buy 2 new 2405 diaphragms I'll have to use
the pair of Audax, , if by chance anyone has a used 2402, at least pair mine up
for some use I'd be interested in purchasing one phram if they had a spare single.