2435?

[Thom]

Whats the story on the 2435?
Hotest new driver out there?
Piece of crap?
If the information is all out their then sorry to have to waste peoples time but I spent quite a bit of time looking and found little. Does it ever get used with a horn or just a wave guide and just what is a wave guide anyway. Does a wave guide provide loading or just directivity? Is one good or would you want 3 like JBL uses? What is it's range, assuming a proper horn. If you put one in a 300hz horn would that be a joke? I saw some stuff where JBL said flat to 15k and I saw some grumbling about it's top end. Besides being small so JBL can fit 3 side by side what does it have going for it? What are they worth? Any help would be appreciated.
Thank you
Thom

[4313B]

Whats the story on the 2435?
Hotest new driver out there?
Piece of crap?

MSRP on the 2435 is $1,399 each.
The replacement diaphragms are $756 each.
Someone not too long ago was selling brand new 435Be's for less than the cost of 2435 replacement diaphragms. G.T. has gotten his 435Be's on his custom horns to deliver -6 dB at 20 kHz and says he likes them just fine. The cost for the right horns for these compression drivers in a home hi-fi environment isn't trivial (I think the MSRP for these drivers and horns is a little shy of $4,000 a pair). The waveguides work just fine for SR.

Incidentally, the 435Be compression drivers were too expensive to use in the Array Series or the K2-S5800. They can only be found in the K2-S9800.

[Thom]

Is there a spec sheet? If one has the drivers and wishes to use them in a home system are you saying that 1k is the lower limit? What is the proper horn or whatever for a home system? All I have been able to find is mention of them as part of a profesionel unit.

[Zilch]

Find more than you want to know here, including the engineering specs:

http://audioheritage.org/vbulletin/s...ead.php?t=9901

See also:

http://audioheritage.org/vbulletin/s...ead.php?t=6050

I'm using them, RobH, Guido, Speakerdave, others too....

[4313B]

Here's my commentary, while the work is still fresh. We haven't sorted it all out yet, but there were some surprises:

Post #2: The size of the back cap is not the big deal with respect to low-end response we thought it was, at least insofar as frequency response is concerned. Whether the smaller-can 2431 and 2435 sound any good below 1 kHz is another matter. On an appropriate horn, they'll at least play down there.

Let's see some impedance curves of the 435Be and 2435 under identical conditions so we can put this to rest once and for all. Also, both drivers under identical conditions on your plane wave tube.

All I have been able to find is mention of them as part of a profesionel unit.

That's because they are Pro drivers. Zilch can hook you up with some decent SR horns for your 2435's.

[Zilch]

I run them at 1 kHz on 2352 horns. They certainly do well at the high end on those.

I've tried 800 Hz on the smaller waveguides, and 1.2 kHz sounds appreciably better.

People look at that 2435/2352 combo and point out those horns are good for much lower than where I run them, down to 500 Hz, probably.

Well, fine, maybe. I've learned to listen to what JBL engineers say is appropriate. Someone else can make an alternative determination if they like.

Me, I'm working with 2452H-SL, and getting to the point where I can A/B them, now having a second pair of 2352s.

I don't have any of the high-end consumer horns, though I'm trying to acquire one or more for comparison, as is at least one other member here.

There's also the NLA TAD horn....

[4313B]

People look at that 2435/2352 combo and point out those horns are good for much lower than where I run them, down to 500 Hz, probably.

Well, fine, maybe. I've learned to listen to what JBL engineers say is appropriate. Someone else can make an alternative determination if they like.

Doug said 1 kHz for the 2435. He designed it. I have not directly compared impedance curves and plane wave tube responses of both drivers.

[Guido]

I need to bring this up again as it isn't sorted out yet and here is the chance.

The 435Be is aquaplased and do not use ferrofluid? This I don't know for sure
The 2435 isn't aquaplased and do use ferrofluid, this I know

[4313B]

I need to bring this up again as it isn't sorted out yet and here is the chance.

The 435Be is aquaplased and do not use ferrofluid? This I don't know for sure
The 2435 isn't aquaplased and do use ferrofluid, this I know

Yes. The 435Be is aquaplased. The 2435 is not.

The backcans actually don't matter at all. The problem was that the original units had their compliances glued which resulted in higher than desired Fs values. It had nothing to do with the backcans as was originally reported during initial Project May conversations. I distinctly remember one conversation at that time wherein a JBL engineer admitted that he hadn't been paying much attention to what Pro had been doing in recent years.

The 1 kHz limit on the 2435 is imposed by Pro because Pro would blow them up if used lower. In fact, in a home environment they can and do go down to ~ 750 Hz on the right horn, same as the 435Be.

Let's see some impedance curves of the 435Be and 2435 under identical conditions so we can put this to rest once and for all. Also, both drivers under identical conditions on your plane wave tube.

Not necessary if one has a unit that was manufactured in the last couple of years. The 435Be has the smoother overall response due to the aquaplas coating. Fs for both should be quite similar.

I guess we now know where the backcan thing came from as well as why the 435Be is more desireable from a JBL Consumer perspective. Funny how it all shakes out over time.

I've tried 800 Hz on the smaller waveguides, and 1.2 kHz sounds appreciably better.

Yeah, you really need to get the right pair of horns. I won't say anything more on that subject for the time being.

[Robh3606]

Yes. The 435Be is aquaplased. The 2435 is not.

Hello Giskard

Yes but what about the ferrofluid?? Do both drivers use it???


Rob

[Thom]

I've only had a chance to barely skim all the information you have made available to me. It will be much help. Many thanks.

[X_X]

Yeah, you really need to get the right pair of horns.

Zilch,

Did you see all the horns in the tent sale?? The good stuff!

Nathan.

[Zilch]

Did you see all the horns in the tent sale?? The good stuff!

Yup. Thank you, Nathan. Got my second pair of 2352s there a couple of weeks ago.

[Thom]

I'm having trouble seeing what makes this thing so special if you're not trying to put three of them in a shoe box, but I'd be the first to admit that I sometimes overlook things. I'd sure rather carry one up a hill than a 2445 but that's not exactly the point. I jumped when I saw beryllium but from what I have read so far their results were somewhat different thanTad's. Their goal must also have been as I'm sure they're quite competant. Or have I read wrong. I thought the purpose of beryllium was extended highs.
Also, in a home enviroment, is ferrofluid a plus or a minus? Isn't it primarily a heat conduit? JBL has a picture of the diaphragm at 15k and the surface isn't broken up but that's not what I get from the scant reviews?

Do the horn adapters always have to be used with a smaller driver and larger horn and never the other way?

[Zilch]

Down-adapting creates a resonant chamber. I have never measured the consequences, though I doubt they'd be desirable.

It's beryllium what makes them special.

They are not TADs.

Bottom line of my experience is they do not "push" gracefully much beyond the pistonic mode.

That's plenty high on the right horns or waveguides, tho....