PDA

View Full Version : JBL SRX/STX series: 18" 2268 out, return to the 2242 or go with the 2279



Bruno_du_13
02-10-2016, 07:58 AM
Hi,

A question I have about recent 18" JBL units:

In the rather recent serie SRX, there was the sub 728 and the full-way 738 using the 18" driver 2268H, a neodym double-differential driver.
This driver was supposed to replace the 2242 because of its similar bass response and maximum SPL, with low distorsion for both, and lighter weight for the 2268 (Neodym magnet). 2268 exhibits a little less efficiency but handles more power with less thermal power compression.

Today this 2268 seems not te be used anymore:
. in the new STX serie the 18" have been replaced by either a double 15" 2226, slot-loaded design (for the full range STX735), or .. an older/weighter 2242! for the 718 or 728 sub.
. in the SRX serie, the 18" is used only for subs, and the 2268 has been replaced by the 2279 which seems cheaper.

Surprising to see a return to an older, weighter driver (2242 vs 2268) for a more recent serie.

At the same time, in Cinema serie, the double 18" subs with 2241 still exists (4642A), but a new one, same box size, is available using two 2269: a kind of 2268 but with a 3-times higher MMs for extended sub response.

Do someone know the reason for that (2268 back to 2242)? should we understand the older 2242 is (or sounds) better? :blink:

Thanks

Bruno_du_13
02-12-2016, 03:56 AM
Hi,

As it seems not so easy to find the response, I sent this thread also in diyaudio.com

If the 2242 is significantly better at souding or measuring, I will replace my 2268. Since it costs #2.000$ a pair, I would like to be sure of my choice :)

Cheers

1audiohack
02-12-2016, 09:19 AM
My memory for time lines is not great but I thought the switch back to ferrite had more to do with price and availability of neodymium.

We joked that all us old SRX guys could be sombody again.

Barry.

JuniorJBL
02-12-2016, 11:06 AM
We joked that all us old SRX guys could be sombody again.

Barry.

That was funny! :rotfl:

Bruno_du_13
02-14-2016, 03:20 AM
OK thanks. So probably a problem of Neodym availaibility / price.

Did anyone heard those 2242 and the 2268 too? I guess both were used on HLA subwoofers, primary the 2242 then the 2268. It would be very interesting to have audio or system engineers, or users opinions about that evolution.

I remembered in sono magazine (french audio pro publication) having read some moderate enthousiast comments about Neodym 15" compared to older JBL loudspeaker. On the paper nedoym+DD sounds well, but should the real life be a little different?
:D

pos
02-14-2016, 04:00 AM
Hi Bruno,
Why not get a pair of 2269H and call it done? :D

hlaari
02-14-2016, 04:19 AM
OK thanks. So probably a problem of Neodym availaibility / price.

Did anyone heard those 2242 and the 2268 too? I guess both were used on HLA subwoofers, primary the 2242 then the 2268. It would be very interesting to have audio or system engineers, or users opinions about that evolution.

I remembered in sono magazine (french audio pro publication) having read some moderate enthousiast comments about Neodym 15" compared to older JBL loudspeaker. On the paper nedoym+DD sounds well, but should the real life be a little different?
:D

2242 and 2258 were used in the HLA subwoofers

2242h HLA 4897
2258h HLA 4897A


Ari

Bruno_du_13
02-14-2016, 08:12 AM
Thank you for your responses.

Pos: I do not want 2269... very large moving mass and low efficiency, 2242 (and 2268) are far better for me. Prefering good 35Hz response "kicky" transducer rather than marshmallow infra sub :)

Hlaari: thanks for the precision. I thought it was the 2268 rather than the 2258. 2258 is a Neodym DD too. Do you listened both 4897 versions, and could you describe it?

BR

hlaari
02-14-2016, 10:14 AM
no, i have not heard the HLA 4897 or 4897a sub
but I have owned 4645C with 2242H and have also try 2258H in the same box and I felt at 2258 were more smooth than 2242H
I see at you have 2268H and CMCD 8" mid driver, are them in Screen array or PD waveguide horn?
were do you cross between the 2268 and 8" mid woofer?


Ari

Bruno_du_13
02-15-2016, 12:58 AM
Hlaari,

In fact I bought a pair of JBL SRX738 5 years ago. I kept the same crossover points (350Hz and 2kHz) but fully active, tri-amped (and EQ'd/time aligned).

http://www.jblpro.com/ProductAttachments/JBL_SRX738.v1.pdf

I use almost the same original components/drivers excepted for the HF section, the 2431 is replaced (as an improvement) by the 2452.

This uses PT (progressive transition) horns for mid and HF, 60 X 40.

I changed the box (rising the net volume for the 18" to 180L, keeping the same size/geometry for the front panel, and using 24mm thick panel, made of Finland birch plywood). The original box was not very neutral.

The result is the same box appearence, with a very clean sound. Even at high SPL. Distortions of 2268 and mid CMCD are really impressive.

Next step could be replacing the 2452 by d2430k (the HF driver of the M2), and why not, the 2242 replacing the 2268 if the 2242 is significantly better - still to be proved!
:)

audiomagnate
02-15-2016, 05:52 AM
Hlaari,

In fact I bought a pair of JBL SRX738 5 years ago. I kept the same crossover points (350Hz and 2kHz) but fully active, tri-amped (and EQ'd/time aligned).

http://www.jblpro.com/ProductAttachments/JBL_SRX738.v1.pdf

I use almost the same original components/drivers excepted for the HF section, the 2431 is replaced (as an improvement) by the 2452.

This uses PT (progressive transition) horns for mid and HF, 60 X 40.

I changed the box (rising the net volume for the 18" to 180L, keeping the same size/geometry for the front panel, and using 24mm thick panel, made of Finland birch plywood). The original box was not very neutral.

The result is the same box appearence, with a very clean sound. Even at high SPL. Distortions of 2268 and mid CMCD are really impressive.

Next step could be replacing the 2452 by d2430k (the HF driver of the M2), and why not, the 2242 replacing the 2268 if the 2242 is significantly better - still to be proved!
:)

I would love to hear those, but as the odds of that happening are very slim, could you post a few pics?

hlaari
02-15-2016, 10:08 AM
Hlaari,

In fact I bought a pair of JBL SRX738 5 years ago. I kept the same crossover points (350Hz and 2kHz) but fully active, tri-amped (and EQ'd/time aligned).

http://www.jblpro.com/ProductAttachments/JBL_SRX738.v1.pdf

I use almost the same original components/drivers excepted for the HF section, the 2431 is replaced (as an improvement) by the 2452.

This uses PT (progressive transition) horns for mid and HF, 60 X 40.

I changed the box (rising the net volume for the 18" to 180L, keeping the same size/geometry for the front panel, and using 24mm thick panel, made of Finland birch plywood). The original box was not very neutral.

The result is the same box appearence, with a very clean sound. Even at high SPL. Distortions of 2268 and mid CMCD are really impressive.

Next step could be replacing the 2452 by d2430k (the HF driver of the M2), and why not, the 2242 replacing the 2268 if the 2242 is significantly better - still to
be proved!
:)

I f I were you I would keep the 2268h I think at it is better woofer with lower Fs and distortions than 2242h


Ari

Bruno_du_13
02-15-2016, 10:50 AM
Audiomagnate,
Thank you for your interest! I will post pics and measurement plots when I will find some time - unfortunately not so easy at the moment.

It's always a pleasure to speak with JBL lovers, even at the opposite side of the planet! :)

Ari,
OK. It's a fact it sounds very smooth.

:cheers: