2421 Al diaphragm on LE85 again

[scorpio]

Hi all,
Information on this might be burried into the archives, but after a little searching; I could not really find it. I am currently using LE85 with standard (old) Ti diaphragm but need to buy replacements as one of the diaphragm is slightly damaged and slightly less efficient. I fancy trying the al diaphragm of the 2421, as it seems that they are so much sweeter.

Question is, I use these in a 2 ways set up, could switching to the Al membranes reduce HF extension in any way? It seems like most posts I seen used these in combination with an extra tweet. I'd like to keep it simple for the time being as the HF is satisfactory to my ears...

Thanks for your help,

[Mr. Widget]

I am currently using LE85 with standard (old) Ti diaphragm...
The original diaphragm for an LE85 is Al.... are you using a pair that have had them swapped out for Ti diaphragms?

Personally I'd go with the 2421s if I could afford it. They do sound better to my ears. It is subjective though and not everyone agrees. The Ti will sound brighter... to me they also sound harsher...

Widget

[scorpio]

Hi Widget,

Honestly, I believe that these babies had a long life before I landed them, they are in less than pristine conditions and have been opened many times judging by the state of the screws, I would not be surprised that the membranes were swapped a few times... but then they were reasonably cheap (for Belgium that is).

I will probably buy the Al membranes as a deal with a new set of LE85 motors in much better conditions and only used for hifi, but thanks for your note, I'll make sure to check for myself which membranes they have.

Regards,

[scott fitlin]

Your LE85,s began life with Al diaphragms! Probably the sound compnay who had them, changed to Ti for more ruggedness!

Ti will sound brighter, and to my ears they are also harder sounding!

Al is the way to go, I cant see you not liking them!

Jus my .01 cents worth!

[speakerdave]

I will probably buy the Al membranes as a deal with a new set of LE85 motors in much better conditions and only used for hifi, but thanks for your note, I'll make sure to check for myself which membranes they have.
That's a good idea, because the ones you have could well need a remag by now.

Lancer recently suggested the powder-coated Ti diaphragms for the large format JBL drivers. There was also a powder-coated Ti diaphragm made for the 275. Don't know if it's still available.

David

[Zilch]

Early 4430 two-ways were made with 2421's, i.e., the equivalent of LE85's with aluminum diaphragms.

In my own testing of old LE85's I was surprised to find that they actually had better HF extension than 2426's with titanium diaphragms.

I agree with the others that the aluminum sounds sweeter, and I would have no concerns about losing HF extension.

It seems JBL switched to titanium in part because of aluminum's limitations in high-power sound reinforcement applications. Aluminum is just fine, perhaps better, even, in normal home hi-fi use.

I'll be swapping in some diamond-surround aluminum diaphragms myself to test this thesis here soon....

[scott fitlin]

Early 4430 two-ways were made with 2421's, i.e., the equivalent of LE85's with aluminum diaphragms.

In my own testing of old LE85's I was surprised to find that they actually had better HF extension than 2426's with titanium diaphragms.

I agree with the others that the aluminum sounds sweeter, and I would have no concerns about losing HF extension.

It seems JBL switched to titanium in part because of aluminum's limitations in high-power sound reinforcement applications. Aluminum is just fine, perhaps better, even, in normal home hi-fi use.

I'll be swapping in some diamond-surround aluminum diaphragms myself to test this thesis here soon....I remember when they introduced Ti diaphragms! Under severe sound reinforcement use the Al phragms could be shattered, but they were REALLY powering and pushing them hard! Ti didnt shatter and was considered to be more rugged and could withstand alot more abuse! The tradeoff was the Ti phragms didnt have as nice and crisp upper mid and top end. For some it was worth it, for me it never was! In home use, I seriously doubt you could play them loud enough to do this kind of damage and stay in the room!

[scorpio]

That's it, I got a good part ex for a pair of sealed LE85 in excellent cosmetic conditions to replace my battered ol' ones. Still have to play with the levels to tune them properly to the low end but all I can say is :D :D :D


Aluminum rules, I'll look at coke cans with a different eye in the future!

And you're right, the tope end is more extended if any (that's without mentioning the extra clarity)!
Thanks all!