2231A to 2235H ???

[John]

If you recone a 2231A basket with a 2235H kit is it the exact acoustical equal to a 2235H unit

[4313B]

AlNiCo isn't SFG ferrite but it's the best you can do.

[John]

So are you saying Yes? as far as acoustics go,and a little different in power handling due to better heat venting in the H basket.?

[4313B]

Lower distortion in the SFG ferrite assembly along with better heat sinking for greater power handling. Some people can hear the difference, other people couldn't care less.

[Chas]

AlNiCo isn't SFG ferrite but it's the best you can do.

Giskard, I thought JBL did SFG because they had to - because of ferrite. Have I got that wrong?

[4313B]

They did do ferrite because they had to, but plain ferrite sux so they came up with SFG ferrite. I posted the tech sheet all about it somewhere on here. The new AlNiCo assembly in the 1500AL fixes all the "problems" with old AlNiCo V as well as using all the goodies associated with the SFG ferrite assemblies.

*****

Here's something:
http://audioheritage.csdco.com/vbull...ead.php?t=4746

[mikebake]

TThe new AlNiCo assembly in the 1500AL fixes all the "problems" with old AlNiCo V as well as using all the goodies associated with the SFG ferrite assemblies.

And THAT, friends, is why Widgets shipment is all the envy this week!..............

[4313B]

He finally got them?

If anyone wants 1500AL's, now is the time to order them while Harman is in chaos.

[mikebake]

He finally got them?

If anyone wants 1500AL's, now is the time to order them while Harman is in chaos.

http://www.audioheritage.org/vbullet...ead.php?t=4738

Scroll down.

$? per driver?

[Don McRitchie]

Background on the 1500AL and its relationship to the evolution of JBL bass drivers can be found here:

http://www.audioheritage.org/html/pr...ogy/1500al.htm

[JBL Dog]

Lower distortion in the SFG ferrite assembly along with better heat sinking for greater power handling. Some people can hear the difference, other people couldn't care less.

I'm in the process of getting a set of 2225H's reconed as 2235H's. Their future home will be in 4343's. I'm going to keep the 2231A's. Should I decide to sell the 4343's, they would be more valuable with original equipment installed. However, the 2235H's sound amazing in that cabinet!

This message comes from JBL Dog

[GordonW]

Bottom line, if the 2231 alnico magnet is fully charged (re-gaussed), and the woofer is in a multi-way speaker where it doesn't have to go very high (ie, like a 4343 or its ilk, where the low-pass crossover is 290 Hz or so), then it'll be VERY hard, if possible at all, to hear the difference between a 2231 frame vs. a 2235 frame, both re-coned with a 2235 kit.

If you're dealing with a more "wide-range" application of the 15" woofer (like say, a 2234 in a 4435, where it's used up to about 1KHz), then the lower IM distortion of the SFG magnet assembly MAY make enough of a difference to side with the 2235 frame over the 2231 alnico. But, it'll stlll probably be a pretty subtle difference, unless you're running the driver to a high excursion level frequently...

Regards,
Gordon.

[4313B]

Exactly! Just because the guys at JBL can hear the difference doesn't mean we out here in the field can.

[GordonW]

Yeah, I tend to sell the alnicos to collectors, and use the SFG drivers, out of general principle... but it's still possible to get a lot of good ol' "boogie" out of those old alnicos...