If the D16R2410 can be used in an LE85/2420, how does it differ from the D16R2420? I know the LE85 has a more massive magnet assembly than the LE175 (to extend bandwidth), but are there any differences in the diaphragms?
If the D16R2410 can be used in an LE85/2420, how does it differ from the D16R2420? I know the LE85 has a more massive magnet assembly than the LE175 (to extend bandwidth), but are there any differences in the diaphragms?
This has been asked before, but never answered.Originally Posted by Beowulf57
Okay...I'm with you...This has been asked before, but never answered.
Well, I have two OEM 2410 phragms in my 2410's here on my workshop shelves that I have never plugged in.
I have the LE85's out of the L200b's just hanging out. I also have some 2421's with OEM phragms. Why don;t we figure this out?
Scotty.
One step above: "Two Tin Cans and a String!"
Longtime Alaskan Low-Fi Guy - E=MC² ±3db
Excellent! As a start, are the 2410 and 2420 diaphragms 8 ohm or 16 ohm? Similar DCR's? Can you visually inspect the diaphragms for differences? Ideally, one would run a sweep on the two diaphragms under comparison installed in the same driver...however that's a fair amount of work and requires swapping diaphragms...if you are equipped and up for it!?
At one point, somewhere, probably on this forum, I read that supposedly the 175 diaphram was too light for use in the LE-85 motor assembly.
Seems to me that if it were lighter than the LE-85 diaphram, it should have a more extended high end than in the LE-175 motor and as long as these are kept in the home at tolerable levels, this really shouldn't be a problem.
So I am still wondering:
Is the "2410" or the "2421" the modern direct exact replacement for what came in the 175?
I understand that there are several diaphragms that will fit; I'm wondering which one is the closest to an exact match?
If running these with a stock, VERY Vintage N1200, would the Titanium options offer any advantages over Aluminum types other than durability and price, subjective sonic qualities aside?
Mine happen to be 16 Ohm models, will switching to 8 Ohm make them any more flexible beyond network compatibility with specific networks?
Thomas
Based on my knowledge of other JBL parts nomenclature, I would assume the D16R2410 is the exact replacement for the 175. At some point during the 70s all of the consumer drivers' replacement diaphragms were given the pro model numbers. Since JBL does not produce identical parts with different part numbers, (to my knowledge) the D16R2410 and the D16R2420 diaphragms while outwardly identical must be different... perhaps the mass as Todd suggests.
The D16R2421 diaphragm is certainly not identical as it has the newer diamond pattern surround design. as do all of the titanium models.
Widget
It does make sense that differing part numbers imply different parts...but it is still unclear what that difference may be? Both the LE175 and the LE85 are rated at the same continuous power of 30 watts. Both were originally rated from 500Hz, the only difference being the top end: LE175 to 15KHz, LE85 to 20KHz. This was due to the larger magnetic structure in the LE85 which increased the magnetic flux density from 16,000 to 19,000 gauss. Given that most of the power is in the lower region of the bandwidth, both units have identical power ratings and identical sensitivity above 1KHz (59dB at specified input), I'm not sure why the D16R2410 diaphragm would be lighter?
I'm not sure why it would even exist, but the fact that it does exist makes me believe there is likely a difference. If it was identical to the older D16R2420 diaphragm, then why wouldn't it be listed as a replacement option for LE85s? Currently the "recommended" replacement for the LE85 is the D16R2421.
Widget
A similar situation arises with the 2405/077. While functionally equivalent, they do/did list separate diaphrams. As we know the 077 diaphrams had the blue rings while the 2405s had the gold rings. On the Behringer 61-band RTA, my 077's and 2405's show slightly different spectra.
Is this a large enough sample to rule out simple unit to unit variation? As in could one observe this amount of difference between two 077's or two 2405's?
Small sample, but the two patterns were pretty much distinguishable. Most of the difference was below the typical crossover frequency, but is evidenced by using pink noise and a simple cap of about 4 mfd.
No, the sample size wouldn't be conclusive, and a Behringer test is hardly conclusive. That said, there is a thread where the different ring radiator diaphragms were physically compared and the diameters of the inner aluminum rings are measurably different. The diaphragms are different, each one specifically designed for it's application.
Widget
Hello edgewound, i have a pair of 2425's purchased, day one, which seemed then like a good idea for extended life & durabilty in my LC9-A Horns.
I have four 2470's & spare diaphragms with excellent fs damping & very smooth artifact-free response. The 2470 motor mass contributes significantly here.
Can you tell me what to expect from the 2425 equipped with 2470 diaphragms.
cheers herki the cat
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