Hi,
what are the differences between these woofers?
Are they electromechanical and cosmetics?
Could be possible to replace one of them by another for a 4301B?
Thanks.
Hi,
what are the differences between these woofers?
Are they electromechanical and cosmetics?
Could be possible to replace one of them by another for a 4301B?
Thanks.
116A = alnico magnet
116H = ferrite magnet
you can learn a bit about the background here: The Great Alnico / Ferrite debate
Also check out the L19 and L19A Technical Manuals. L19 uses the 116A, L19A uses the 116H. Slightly different DCR specs. Cone kit for each is the same. LF network is the same. I would bet any acoustic/sonic differences would be difficult to discern, although other posters have noted distinctions between alnico/ferrite versions of a different model transducer. Maybe someone with more technical knowledge could advise whether any electromagnetical problems could occur by a less than a pair substitution.
Any cosmetic differences?
How I can distinguish both models with a look?
B.R.
116A alnico magnet is a simple dome on the rear.
116H ferrite looks more like a wheel.
I do find measurable differences between them, but would have to do that with multiple units to confirm statistically before concluding anything.
"H" obviates any potential demag problem, so I prefer using that version for closed-box Minis.
Edgewound...JBL Pro Authorized...since 1988
Upland Loudspeaker Service, Upland, CA
ob·vi·ate(bv-t)
tr.v. ob·vi·at·ed, ob·vi·at·ing, ob·vi·ates
To anticipate and dispose of effectively; render unnecessary.
'Sounds like Zilch is correct to me...
John
Edgewound...JBL Pro Authorized...since 1988
Upland Loudspeaker Service, Upland, CA
The best information I have is the T/S parameters for the two driver variants are the same, so the fundamental performance in any alignment would be as well, as I understand it. The "A" and "H" versions are equally wimpy, and thus well-suited to closed boxes.
I choose the "H" ferrite version because GT suggests the Decade "As" are among the group of drivers most sensitive to potential demag with drive, and because the small closed-box alignments are inherently inefficient and require more drive to achieve SPLs comparable to the vented alignments in which they are more conventionally employed.
My major problem is that I cannot get contemporary factory kits to fit the vintage motors, and I've never seen any refoamed ones of either type approach the originally spec'd 28 Hz Fs. It may well be I'm using too-heavy aftermarket foams here, and I want to check that out in comparison to factory kit recones....
Edgewound...JBL Pro Authorized...since 1988
Upland Loudspeaker Service, Upland, CA
Edgewound...JBL Pro Authorized...since 1988
Upland Loudspeaker Service, Upland, CA
My reconer has the kits, but the voice coils do not fit in the gap without rubbing. We have cleaned, polished, and honed, all to no avail.
I have advised him to send the cores and the kits to JBL Service and let them deal with it. Those kits are NOT cheap, as you know....
Edgewound...JBL Pro Authorized...since 1988
Upland Loudspeaker Service, Upland, CA
Hi Zilch,
Regarding the 116H recone kits, did you ever get this voice coil rubbing issue sorted out?
I am assuming that the 116 frames' gaps were nice and round and correct, honed (as you mentioned). What did you eventually do?
Regards,
Bart
When faced with another JBL find, Good mech986 says , JBL Fan mech986 says
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