A 416 dilemma. What to do?

[Panomaniac]

Thanks guys.
Yeah, I could not in good faith sell these knowing they are so far out of spec. Not right for the buyer, and not right for the Altec brand.

Bill told me several times that he had never seen Alnico that would not recharge. Told me it was impossible to beat Alnico so badly it would not take a charge. And yet these didn't. But that's not what I've heard from some other Altec heads. Who knows?

GPA did tell me not to worry about the measurements. "Just listen to them." I did, they suck. GPA did say "they should be pretty close to spec" but would never tell me what that was. Wouldn't look it up for me. When I finally did find specs, they were obviously way out.
A frustrating experience all around.

You're right Robert, a lot of shipping charges in these two! No idea if the magnets can be replaced. Gotta be near as expensive as new drivers, tho.

Oh well.... a couple of big ashtrays.

[Art J.]

2 magnets bad at the same time?????? Doesn't sound right.
Did you test with the compass and ruler method referenced with a good one?

[Earl K]

I called Bill to ask about it. He said he was pretty sure they remagnetized them, but they could have slipped thru. So I sent them back. They zapped them again. But they hardly changed at all. So I had to pay for the 2nd remag. Both Bill's measurements and mine show weak magnets, one more than the other.

So here they sit, fresh cones, weak magnets. What to do with them?
I can not honestly sell them knowing the magnets are shot. Or may I can list them on eBay cheap with full disclosure? Really don't know what to do with them. Would like to get a little money back out of them, but do not want to cheat the next owner. Right now they're just taking up shelf space.

So both 416-8a(s) have weak magnets according to Bills measurements and can't hold a charge .

Some conjecture ; perhaps some 416s from the LTV era just had less magnet to begin with . That wouldn't be that far fetched IMO .

Remember, this is the same management team that thought it was a brilliant idea ( not ! ) to create the 804/806 by removing alnico ( surplus really ???? ) from the 802 to then foist upon the unsuspecting buying public ( who by & large at the time, had little measurement capacity to understand the consequences ).

- What to do ? DIY forum has a lot of guys in love with the OB concept ( usually using high Qtc drivers ) . Your Qtc figures show your woofers are now closer to that OP standard .
- Market your woofers to them as a compromise solution ( some guys want their cake & the ability to eat it also / ie ; want Altec with its historical low Qtc(s) but then implement them in OBs which require high Qtc ) .

<> cheers

[airboss]

You'll spend more money probably but here's a plan. Watch E-Flea for early (no step to cast supports) 418B, I think they are the same mag structure and I'm sure they are the same basket. I've seen blown 418B (white ones) go for $35. Green ones are rare. I have no idea how the magnets come off, but some research may make this hairbrained scheme a viable plan.

Dan

[gearfreak]

I like the OB (thinking outside) of the box idea.
Simiarly, maybe they'd be useful as passive radiators for someone?

(perhaps requires removal of the magnets... possible?, never uncorked mine to see what was underneath the cover)

[Panomaniac]

Well, I have thought about open baffle. "Rare! Altec Open Baffle Woofers!"
Not the best choice, but hey, I've seen lots of guys run less optimum woofers on OB and love it.

Also thinking about the magnet. Does it come off? Will it go back on straight? You know that bolt you can see thru the hole in the dust cover. Does it hold the magnet on?

Gotta measure them again.
Still thinkin'......

[bfish]

Chunk 'em and chalk it up... life goes on.

If you want, I'll send coordinates to my Cache of Monumental Failures. There's always room for more.

[GM]

Bill told me several times that he had never seen Alnico that would not recharge. Told me it was impossible to beat Alnico so badly it would not take a charge. And yet these didn't. But that's not what I've heard from some other Altec heads. Who knows?

GPA did tell me not to worry about the measurements. "Just listen to them." I did, they suck. GPA did say "they should be pretty close to spec" but would never tell me what that was. Wouldn't look it up for me. When I finally did find specs, they were obviously way out.
A frustrating experience all around.

This has been my experience also WRT heat sinking (extreme heat build-up), cracking, chipping. Indeed, it's not uncommon for a crack or chip to increase a slot car motor's overall performance, so short of dislodging the magnet, hitting, dropping it won't necessarily adversely affect its performance. WRT heat damage, it takes >538 deg C to start changing its metallurgical structure to where it can't take a full re-charge, so are there any Altec drivers (or any brand for that matter) with VCs capable of repeatedly getting this hot in a mega-power system for a long enough time to achieve this?

I'm thinking not, but can't find any real world numbers beyond the one Tom Danley noted many years ago that >230 deg C peaks have been measured which is lower than those I've measured. According to these folks, heat affects AlNiCo's loss due to heating at a rate of 0.02%/deg C or 0.46% @ 230 deg C, so completely insignificant WRT audibly affecting a driver's Qts.
http://www.arnoldmagnetics.com/products/alnico/index.htm

Regardless, combined with having already read/heard about enough others with what I consider less than acceptable customer service from GPA, yours was the 'straw' that had me questioning their commitment to folks needing service in general and magnet re-zapping in particular.

GM