JBL 2108H 112A compatibility 4315B?

[uberto]

Hello, i am Uberto from Italy (Northern Italy ...), this is my first post here .. congratulations for the wonderful site .. (sorry for my bad English, I help with the translator of google). I know quite well, "old" vintage jbl. A question for the experts, I have a pair of beautiful 4315b, in perfect condition (ferrite magnets), I bought from, from a store / workshop specializing in assistance that closed, a pair of "very rare" N.O.S 112A (Alnico), I changed foam, obviously disintegrated .. perfect job.

I tried to fit them into my 4315b (the crossover is the same as the 4315A alnico version = 3114A), sound very good, maybe a little better than mine but very well maintained used 2108h (the compliance of suspension "tested hand" of 2108 is higher, probably just because they have always been used in all these years.

Here's the question, given that the two speakers are equal (change only the magnet, alnico in 112A, ferrite in 2108h), doubt about the flow of gauss, the little information I could find, give 112A to 9500 gauss, the 2108 (alnico version), to 10,500 gauss, the 2108h I have no idea ..Since I also found a pair of 2105 first series alnico, "mint condition", I'd like to mount them to the place of my great 2105H .. so you have a full Alnico 4315 (apart from the woofer, my 2203H are perfect) , the woofers alnico are those that tend to be demagnetized with the use ..Any advice?

Greetings Uberto

[speakerdave]

There are many details in the history of the changeover to ferrite that I don't know, but I think the changes you suggest are OK if they sound good to you. The raw distortion numbers were improved when JBL engineering finished the changeover to ferrite, but the original goal of that work was to make them good substitutes.

[uberto]

Thanks .. I know the history of the passage of the magnets in alnico those ferrite ( costs , the war in Zaire late 70's etc etc ) . Doubt biggest concerns the perfect compatibility of the magnets (the flow of gauss ) , between the magnets of the home version 112A mounted on the system L212 and the 2108 alnico mounted on the first two versions of the 4315 , should be the same .. but I'm not 100% sure