Foam for non-loading cap driver?

**robertbartsch** · October 27th, 2009, 08:49 PM

I'm restoring a pair of 802 compression drivers with new GPA frams and a fresh re-charge.

The cores came with loading caps but I wan't to delete them.

Where can I buy foam to install on the back of the driver cover?

Thx.

**just me now** · October 27th, 2009, 08:57 PM

Was there foam on the back covers?

I'll go check...

**just me now** · October 27th, 2009, 09:04 PM

looks like a felt pad to me...

**robertbartsch** · October 27th, 2009, 09:14 PM

802 Driver covers are bare - no foam.

**bowtie427ss** · October 27th, 2009, 09:30 PM

The 3/8-1/2 in thick felt from a boot liner is perfect for this task and very close to the same material Altec used.

**Old Guy** · October 27th, 2009, 09:34 PM

Originally Posted by robertbartsch

802 Driver covers are bare - no foam.

Nope you are talking about 808 covers.

802 covers have felt.

AFAIK no Altecs use foam, for that reason I do not recommend it.

Try GPA I believe they have felt. Probably a craft supply would have it. Used to be common , not so much now. A fabric store is certainly a possibility.

**bfish** · October 27th, 2009, 11:00 PM

Waxman felt pads at WalMart, Lowes and others. In the furniture slider section. Pack of 2-4"x6"x1/4" felt sheets for like $4 and change. Even has peel-n-stick backing. Scissors and the skill to cut a circle not included.

**bowtie427ss** · October 28th, 2009, 08:08 AM

Nope you are talking about 808 covers.

802 covers have felt.

Well, for the sake of discussion(no argument intended) i would have to both agree and disagree. I'd wager that most 802's shipped from the factory(after a certain point in time) in systems with 500hz XO had loading caps instead of felt(9846's), but i wouldn't observe it as a rule. In fact, i sometimes wonder if there were any "rules".

I would also note that the 23744 equipped 806 type drivers in my 9849's also have loading caps and no felt, as well as my early '75 production 23744 equipped 604-8G's. I was indeed surprised to find loading caps in all of these places.

**Old Guy** · October 28th, 2009, 11:10 AM

The loading cap became more common as amplifiers got bigger.

Traditionally, 802's did not have the loading caps... or at least that has been my experience.

I would bet the majority of 802's don't have them. Almost all the 1950's and 60's production for instance.

Things got a bit iffy in the 70's, as amp power climbed so did diaphragm failures...bet I sold a couple thousand Altec frams, we ordered 50 at a time because there was a price break.

I suspect our perspectives are due to in my time few had them, in your time they were more common. I don't think there is any question they sound better without.