2450 Dia

[Zilch]

The "List" as I see it

Engineering design specs for:

2450
2450SL
2451
2451SL
2452
2452SL

Also, what is 2450SL-A diraphragm. Ribbed, with Aquaplas?

D16R2450SL is not on the price list. Is D16R2451SL the same?

Is the 475 diaphragm the same as either of the available Pro "SL" diaphragms?

[stevem]

Any info on these yet?

[Zilch]

From the pic he posted today, Giskard may still be at JBL, looks like....

[Zilch]

Ah-HEM!!

http://www.jblpro.com/installedsound/support/index.html

2452H-SL, PT-F1010HF, NL200t3 biased and bypassed, L88 plugged.

Red = HF only, windowed.

Org = Full system, unwindowed.

[Who's J.R.? :dont-know]

[Zilch]

Per request, impedance, phase, and response plots for 2 units 2452H-SL, on PT-H95HF waveguides. Frequency response is shown at both 10 and 5 dB/division. Raw FR plots unsmoothed, filtered ones 1/6 octave.

I'm not seeing any breakup mode here, unless it's at 10 kHz; I doubt the waveguides are masking it.

The two units are not perfectly matched. Don't know if I'm going to do anything about that, tho, at this point....

Sorry 'bout the wide impedance/phase plots. I want to show max resolution for TimG's analysis.

VP7215/95 frequency response, bottom. Same driver and horn, filter/EQ unknown.

Looks like #2 (blue) is the "good" one from that; I doubt they EQ above 10 kHz.

[Measure your drivers, folks, even (especially) the $1315 ones.... ]

[TimG]

That response graph is very impressive. That is the best response curve I have seen from any JBL compression driver yet. I don't see any break up in the response curve before about 19kHz. I found the price, at $1315 it is less expensive than the list price for the 2435HPL. Maybe some B-stock will turn up some day that I could afford. If you have 2 of those and 4 2235H's, you really need to throw them together with an Everest style crossover and let us know how they sound with your 2452 horns.

Here is an example of a different large format compression driver with obvious breakup in both the frequency response and impedance sweep curves. This example is the B&C DE610. I would not try to use a driver like this above 10kHz.

Here is the frequency response and the impedance curve. Notice the peaks in response and the corresponding peaks in the Imp curve where part of the diaphragm is no longer behaving like a piston.

[Zilch]

One 2235H will have to do until Mr. Widget makes me a

V--E--R--Y- -W--I--D--E

horn....

[Not bad on PT Waveguides, actually, and the compensation is, well, uhmm, "straightforward...." ]