Admittedly, I'm not the most competent of diaphragm swappers, and we've discussed alignment issues in other threads here recently.
SO, I'd very much like to see others' FR results with "SL" diaphragms in comparison to uncoated here.
IIRC, YOU've got some, Earl, no?
- Yes, I have a D8R2450SL installed into a 2440 ( remagged ) driver ( lots of gaussOriginally Posted by Zilch
- I could post a pic of a RTA shot from a Behringer EQ, ( unfortunately, no CLIO here and I thought these rough type of RTA shots had been banished) .
- The problem is , I don't have any large format cd horns to mate it up to ( just some older exponentials ). So , it'll be apples & oranges between your results and mine. Do you want to see a 2311/2308 combo ?
If you've got a stock diaphragm 2440 for comparision, that'd be worthwhile.
OR, borrow a 2380(A) from a forum pal up there?
Actually, lots of members have stock on 2311/2308 for comparison.
So, post it, YES!
Do you find the same, i.e., smoother, more "natural" sounding?
- I haven't had any intimate listening sessions with that setup for going on 2 years this summer / but / yes ( from memory ) the aquaplas tames most of the "zings & zangs" that one gets from these 4", 8 ohm titanium diaphragms. Even with the aquaplas the 8 ohm titanium diaphragm has more "splash" ( 6K & up ) when compared to an Altec 288-8K ( as a for instance ) .
- "Splash" can be "fresh" , "exciting" , and even "open-sounding" ( at its' best ) / though this "trait" easily gets out of hand and leads me toward ear-fatigue. I never, ever get fatigued from my 288(s) .
- FWIW, I find the stock 4", titanium diaphragms to be just about unlistenable ( at home on my typically small horns ). The same holds true for all the 3" european diaphragms that I've tried here . The D8R2450SL was "listenable", if that helps . I liked it more than a D8R2441 diaphragm in a 2441 or 2440 magnet .
EDIT: I'll post something this evening .
No,,,,That's not going to happen. I'll have to revise that timeline into tomorrow sometime ( I got sidetracked working out a tank circuit for a 2012H ) .
That'd make these 16-Ohm ones "just right," then.
I gave 'em (2450's w/D16R2450SL) JBL standard 2380 CD compensation (1.2 kHz FFBREQ in 5235). That confers too much VHF, obviously, but you jus' KNOW where I'm headed with these, now....
"Next-generation" HF driver: 2452H-SL titanium damped 4" diaphragm 1.5" exit:
http://www.jblpro.com/installedsound.../VP7215_95.pdf
PT-H95HF waveguide....
So, are you happy with the Dogs' dias?That'd make these 16-Ohm ones "just right," then.
I gave 'em (2450's w/D16R2450SL) JBL standard 2380 CD compensation (1.2 kHz FFBREQ in 5235). That confers too much VHF, obviously, but you jus' KNOW where I'm headed with these, now....
What's a "tank circuit"? (wondered John, eyeing his two 2012H's still NIB...( I got sidetracked working out a tank circuit for a 2012H ) .).
Also, I stopped by Zilch's today and had a listen to the 2450's with aquaplas'd diaphragms playing through 2380A's. Even just 2-way, I found them highly listenable. Unfortunately, there wasn't a setup for comparing them against the standard titanium diaphragms, but they definitely sounded quite good to me - vocals, piano, cymbols - I really didn't detect what I would call any harshness at all. 'Also listened to the same setup crossed over into 3-ways, though I'd have to do some long comparisons to determine which HF matched up best. But overall, I was impressed with how well those 4" diaphragms with 2" throat and big flat-front bi-radials sounded. I'd still like to hear the 2380's compared with 2397's sometime...
John
We're certainly having fun "investigatin'" them.
"SL" isn't mainstream; not much information available. But if JBL's latest offerings, both consumer and pro, are indicative, it's a worthy pursuit....
Is there any info on this driver? How is it different from a 2451H or a 2450SL?
Okay ;
- A "tank circuit" is a colloquial name for a LCR-type "resonance trap" circuit using "paralleled-components" and usually used inline , ie; inserted in series within the audio circuit ). The "Everest" has one in the woofers' passive circuit while the L220/222 has one in the passives' midrange circuit . I think the resonant frequencies are somewhere around lower 300(s) and about 1450 hz respectively .
- In my particular case. A 25uF Solen cap was paralleled to a partially unwound 1.6 mH coil and then these were paralleled to a 5 ohm resistor . The whole mess was inserted in series on the 2012H . The calculated resonance value for 25uF with 1.6 mH = 796 hz. My measured resonance point is @ 820 hz which just happens to work out to be a resonance point for 1.5 mH & 25 uF ( actually 821 hz is the calculated point for those values ).
- My inline filter has a very broad based effect, showing measurable attenuation between lower than 400 hz & up to 2000 hz / so it has pretty low Q ( though I haven't done any calculations to support this observation ) .
- This filter does a very nice job of flattening the response of this 10" for intended usage in a small ported enclosure ( @ .6 cu' tuned to around 110 hz ).
-I imagine that the usable db rating shifts to around the middle 90's ( maybe 94/95 db , though I have yet to measure this ).
- That figure happens to be in my target range since I want to eventually ( think extreme future tense ) parallel this midbass with a ME150h woofer to create a higher sensitivity, asymmetrical MTM . Therefore I need to jump through some filter hoops like this, even when the whole sheebang is meant to be crossed over electronically .
No clue. I just found it yesterday on a tip from Johnaec regarding new offerings at JBL Pro.
It seems from the product response curves that they're not pushing the UHF terribly hard, but the VHF appears to carry higher than I have measured with 2446J, for example.
That PT-H95HF waveguide is the deepest (by substantial margin) of the PT family I've evaluated here, and probably the best sounding. With previous product offerings using it, JBL cautions that, for optimum performance, delay should be incorporated on accompanying driver(s) to compensate.
When I first saw the 90° x 50° spec, I was hoping the PT-F95HF would appear. Not yet, alas....
Perhaps Giskard has (or can obtain for us) some info on the new 2452H-SL large-format driver?
Check this out:
http://www.jblproservice.com/pdf/Dis...els/2452HJ.pdf
The SL version probably has an Aquaplas coating.
Is that because of all the mattresses, old tires and catcher's mitts they hafta put in the 16 ohmers to slow down the electrons?
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