Altec 604 C diaphragm differences - Help

[Altec Best]

Although this is quite possible, they are both 1957 production dates and they have been together since new which means they were exposed to the same atmosphere, storage, usage etc.. I would hope that even if a little weak that they are equally weak.. If they came from two different sources I would be more inclined to go along with this theory.

If I sent a speaker out with a perfectly fine diaphragm I think I would get the old part back!! especially given the rarity and price of an original fram!

Even speakers just manufactured in sequential order will have slight variations especially with Alnico... No 2 Alnico magnets will hold the same charge,they will all have slight variations.IMHO.. Just putting power through them will weaken a motor especially after 50 years and if the volume is quite high it will weaken them even quicker..

I can assure you they'll never see my business again, The only reason I sent it was in case they needed to be rebuilt so they would both sound the same. Over 500 bucks in shipping, took at least 4 calls to them to get them on their way back home. They were done the first time I called, three weeks later I was still calling. and in the end I see the phram replaced in the one I told them had nothing wrong with it. just my .02

That is a shame since they are the only place to get original Altec parts.I have posted this several times on this board before..If you send in your drivers to GPA for a rebuild ? No care will be given to the old diaphragms.I posted this about 802-8G's and the lite diaphragm 23744.. Bill doesn't keep them he throws them out..he manufactures new ones..

All this phram talk got me wondering about what I have in mine. I have 604Ds which are similar to late model Cs. I popped the cap off the back, but didn't have time this AM to go further.

These are my phrams:



Is there a number printed in the other side? Can I remove it safely?

Yes on the inside lip underneath there should be a 5 digit number. This is the model #

Look here Alan this is a 23744 diaphragm.


HPIM2345 by Altec Best, on Flickr

Sorry to hear of this. I feel fortunate that i was advised long ago to NOT send working diaphragms or salvageable cones when having anything rebuilt as you will not see them again.

It is also a good idea to tape a note to each component specifying the exact work you want done to it. There's just no substitute for good communication.

Exactly ! I posted this awhile back myself.. If you want to keep your old diaphragms it's best to take them out first before sending them anywhere.. Bill himself told me several times to put a note in the package on what you want done..He has so much work if there is no note he will just rebuild the whole driver,woofer,etc...

You post what you want done.Record all pertinent information and write it on the note.Copy one for yourself..I used Wordpad and printed 2 copies one for me and one for Bill and never had a problem.. The only problem I had with GPA is it took 2 months to receive a pair of 416-8B's one time that he had to recone due to failed spiders from storing face down for many years.

Always record serial #'s too..