A 416 dilemma. What to do?

Here's my dilemma and saga. GM knows it well, as he followed it step by step.

About a year ago I bout a pair of 416As off eBay. They were reasonably price for the shape they where in. Had come out of a pair of A7s somewhere in Jersey. But had been reconed with MI cones. They were pretty beat.

As bought, they worked, but definitely needed a recone and remag. T/S parameters showed weak magnets. So I dropped then off in OK city into the hands of Bill H. He remagged, reconed and sent them to me. Lovely cones, but.... magnets still weak. Qts of about 0.5 on one, 0.4 on the other. No good. Vas not close either. They're way out of spec.

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.

I gave it some thought and couldn't come up with any practical use for them.

I will commend your honesty for not trying to pawn them off on someone else.
Good man. :)

Seeing the magnets will not recharge they were probably from a bad batch. I wonder if there are more out there from a similar build date?

I have to agree with Nipper Good Man.:2thumbsup: Pano there are too many of those people out there already.If you try to sell with full disclosure then nobody probably would buy them,and then your stuck with more cost in Ebay fees.If it were me I would save as much parts from them as I could the new cones,etc.. and eat the cost and move on lesson learned.If you sell them knowing that they can't be repaired, I couldn't do that to someone knowing how hard I work for my paychecks.Do you remember who you bought them from I would want to have a chat with them.Who knows maybe you can get a refund.Although it was a year ago. ;)

Pawning them off from one person to another just makes for a whole bunch of pissed off folks.Tough Call but if anyone can make the right one it is you my friend :2thumbsup:

What did Bill say? Had he ever heard of such a thing?

You probably have incurred a lot of shipping charges on these already but I would assume Bill could fix them, perhaps with new mags since he is manufacturing new alnico woofers of similar design. ....just a guess - really...

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. :Thinking:

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?




:)

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Originally Posted by Panomaniac

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.

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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

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

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)

Well, I have thought about open baffle. "Rare! Altec Open Baffle Woofers!" :D
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'......

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. ;)

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Originally Posted by Panomaniac

. . . . They were pretty beat . . . .

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Possibly the problem is somewhere in the "return circuit." That would effect the reading in the gap as much as a problem with the magnet (I would think).

Not to worry bfish, that's pretty much what I've done for the past year. Written them off.
But every now and again I think "maybe."

Dave - return circuit?

Just a tongue in cheek comment on my part, Pano. Analogous to the great satisfaction and closure I felt at a mock ceremonial burning of my ex's wedding veil after the divorce. :)

A return circuit failure could be a loss of good mechanical contact in the "shell" components, pole-to-plate, plate-to-pipe, and/or pipe-to-plate. The shell is steel, so cracked welds or hidden rust is a possibility. Just as a poor electrical contact adds resistance, poor mechanical contact adds reluctance.

Oh, right. Now I see. Well could be, I suppose. They don't look that bad, but one never knows.

Can they be taken apart? Should I make field coil drivers out of them? ;) Just hate to see any Altec gear go to waste, but it may have to.

Use them in an open baffle; many people that make OBs like them even though they usually sound bad.

Quote:

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Originally Posted by Panomaniac

Oh, right. Now I see. Well could be, I suppose. They don't look that bad, but one never knows.

Can they be taken apart? Should I make field coil drivers out of them? ;) Just hate to see any Altec gear go to waste, but it may have to.

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Let me qualify what I'm about to say with a disclaimer. I used to take speakers apart all the time when I was a kid just to play with the magnets.

Unless the entire speaker frame is made of alnico, my guess is that those magnets will come apart. They may require riveting or welding to put back together. Not difficult when you want to rescue them. It seems to me though, that to rescue an LTV altec frame by distroying an older one would not make sense UNLESS, the basket on the earlier 416/418/421 had been run over by a buss full o' hippies. I'm surprised that Bill H didn't have some sort of solution, ie refitting with new magnet assemblies.

Otherwise I'm with others that say toss them.

I've got two suitable 15" non LTV baskets and one 417-8C LTV. I've got a very early straight 417(so suffix) that is not ling.

Question: Can recones be taken off and moved to a new home, or is that glue forever?

Another option, have Weber re-cone them into a 15" guitar speaker, with aluminum dust covers. Nobody cares about Qts in an open back cab. Might make a nice Vibroverb.

I'm afraid I am not conversant with TS parameters, so my comments here are general, not specific. AFAIK, the only real way to assess the state of charge of the magnets is to measure the flux density in the voice coil gap directly with a gauss meter. Then the readings, made at several points around the gap, can be compared to the driver spec.

I agree with Earl that the LTV era construction may have paved the way for undersized magnets. The 416 was the smaller magnet woofer to begin with, and these cheapskates had recently given the new, downspeced 804A compression driver a really tiny alnico magnet.

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Originally Posted by airboss

Question: Can recones be taken off and moved to a new home, or is that glue forever?.

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If you have the patience of a saint, the steady hand of a watchmaker, enjoy the buzz from MEK fumes, and nothing better to do with your time. I've done it, but I'll never do it again.

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Originally Posted by airboss

Another option, have Weber re-cone them into a 15" guitar speaker, with aluminum dust covers. Nobody cares about Qts in an open back cab. Might make a nice Vibroverb.

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Now there's a good idea! Only I'd try both as-is in a sealed Dual Bassman box. No need for aluminum caps for bass guitar, and the sealed config would add some mechanical damping to compensate the weak mags.

The LTV/smaller mag theory doesn't explain why they're signifcantly different from anything else AND each other.

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Originally Posted by bfish

The LTV/smaller mag theory doesn't explain why they're signifcantly different from anything else AND each other.

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- You're right / my bad , I'm sorry :( / I didn't pay close enough attention to the stated differences between the Qtc of the 2 speakers ( ie ; A = .4 Qtc , B = .5 Qtc ) .

- Well, the causation of the wrong Ts numbers is still a mystery .

Quote:

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Originally Posted by Pano

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.

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- I gotta say, as much as anything, I'm disturbed by GPAs' attitude here ( summed up by Bills' directive of ; "just listen to them" / & then, tied to my paraphrase of ; [they're close enough, you should still like them] & yet, Pano couldn't find "the love" :p within this pair of GPA rehabs ) .

- So what are the lessons here ? Are they ? Don't critically measure GPAs' rehabs ( ie; look a gift horse in the mouth ) / or maybe / just don't have GPA do rehabs on ancient alnico & expect new product performance / or perhaps a reasonable conclusion would be to just buy premium ( ferrite Altec ) product from eBay that a local reconer can service ( ie; no shipping , no flakey alnico to deal with , this is my preferrence ) .
- Maybe one just needs to provide measured TS data from 3 independant sources so that the measurements are considered valid talking points with GPA .

- ( A long shot ); Perhaps Pano never liked ( or was familiar enough with ) the sound of Altec 416s and is therefore causing GPA unwarranted grief .

<> cheers

Bill and GPA has been very fair with me and I have used them several times.

However, I did have one slip up when I asked to have a pair of slot tweeters re-maged and recieved the cores back with the magnets no longer aligned so the noses could not be re-installed.

Anyway, I would ask Bill if the could replace the motors with new alnico.

Thanks guys. This one is a mystery to me.

The guys at GPA were very nice to me, tho they seemed a little overworked. Forgot to send the woofers back, did not supply measurements even tho they said they would both times, didn't look up specs, that sort of thing. But very willing to help and get things right, no problem. Maybe they just need a good secretary? ;)

So anywho.... I measured the darn things again - 13th time is the charm. Here is what I found today and it matches closely with what I found last year.

416A #3325 (the weaker one)

• f(s)= 19.51 Hz
• R(e)= 6.17 Ohms
• Z(max)= 62.81 Ohms
• Q(ms)= 6.162
• Q(es)= 0.671
• Q(ts)= 0.605
• V(as)= 987 liters (34.8 cubic feet)
• L(e)= 1.00 mH
• SPL= 92.28 1W/1m
• M(ms)= 65.18 grams
• BL= 8.57

416 #32745

• f(s)= 18.84 Hz
• R(e)= 7.05 Ohms
• Z(max)= 122.90 Ohms
• Q(ms)= 6.988
• Q(es)= 0.425
• Q(ts)= 0.401
• V(as)= 942 liters (33.27 cubic feet)
• L(e)= 1.48 mH
• SPL= 93.60 1W/1m
• M(ms)= 73.22 grams
• BL= 11.99

So as my buddy John says "You've got yourself a nice set of closed box woofers there, Pano." Gee, thanks John. =(

Well Fs is nice and low, anyway. But Vas is huge and efficiency is low. Calculated BL is low, too. An Altec 416 or 515 should have a Qts down in the 0.25 range and be about 98dB/watt efficient. These are not. Qms is about right, but Qes is high = weak magnet.

I will ask about replacement magnets, for sure. Wonder if it's worth the cost? We shall see.

Yes Pano, in summation those are pretty lousy numbers .

- I still can't let go of the fact that GPA thought your pair were close enough to spec. to ship back to you ( for your listening enjoyment :confused: ) .

- The lesson I take from this is I wouldn't bother sending old beaters to GPA for recharging & then automatic reconing until GPA can confirm that the old alnico has taken a full charge( & therefore is worth reconing ) .

Quote:

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Originally Posted by robertbartsch

However, I did have one slip up when I asked to have a pair of slot tweeters re-maged and recieved the cores back with the magnets no longer aligned so the noses could not be re-installed.

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- Robert, did the 077 diaphragms still fit properly into the gap or did they bind when you tried to fit them in ?
- Your problem is also quite intriguing. It sounds like either something shifted in transit or that your magnets were demagged & then remagged ( with the component parts coming loose after demagging & then being remagged while out of center ).
- You might want to contact LHF member "pelly3s" who works for an outfit ( that does recones out of "Springfield MA" ) which also owns a magnetizer .
- They might be able to fix your JBL 2405/077 drivers ( assuming the "slots" are still with you ) .
- Here's a thread to read at LHF which includes pictures of that companies magnetizer . It's possible it doesn't have enough juice to do large drivers / you'd need to ask .


<> cheers

Quote:

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Originally Posted by Panomaniac

I will ask about replacement magnets, for sure. Wonder if it's worth the cost? We shall see.

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I doubt it. Unless 416s have gone back up. It would require a second recone. The screws to remove the motor is under the spider.

Maybe we could have them Bronzed and sell them on Ebay as Rare...

Collectible Bronzed Altecs...:rotfl:


A West Virginia relative won a gold medal at the Olympics..was so proud he had it bronzed....

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- I gotta say, as much as anything, I'm disturbed by GPAs' attitude here ( summed up by Bills' directive of ; "just listen to them" / & then, tied to my paraphrase of ; [they're close enough, you should still like them] & yet, Pano couldn't find "the love" :p within this pair of GPA rehabs ) .

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This is not meant to be a criticism of Bill, but in all my conversations I never found
him to engage like an engineer in the business of details.

"An Altec 416 or 515 should have a Qts down in the 0.25 range and be about 98dB/watt efficient. These are not. Qms is about right, but Qes is high = weak magnet."

I have a pair of JBL d130f that, like Pano?s 416s, are sitting unused because they sound like #$%^. Mine also have the higher than spec Qes values. I wonder if a remag would create any sonic miracles !

http://img693.imageshack.us/img693/9950/d130free.gif

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Originally Posted by sba2

I have a pair of JBL d130f that, like Pano’s 416s, are sitting unused because they sound like #$%^. Mine also have the higher than spec Qes values. I wonder if a remag would create any sonic miracles !

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- Recharging the magnets might help your woofs ( its a long shot ). The too high Fs is pretty worrying . What are the BL and Mms figures for that pair ?

- It's just as likely that both your d130f woofs are reconed with aftermarket parts ( typically Waldom ) and suffer compromised performance as a result . Remagging doesn't help when a speaker has compromised kits in place .
- Look for MW - ###### stamped on the cone to identify Waldom cone-kits .

- IMO, people selling woofers on eBay with aftermarket kits in them ( & not identifying this fact within the sales text ) is tantamount to fraud .

<> cheers

Well as you can imagine, I've become rather shy about this whole remag thing. "Once bitten, twice shy". So how about twice bitten?

Perhaps I was naive going into this, but (almost) everything I'd heard or read up to that point had told me that a recone and remag would make the drivers good as new. I did start out with frames in nice shape, just the cones were not right. Or so I thought.

At this point, I'd want to see real proof that the remag process actually works before I'd drop more money on it. Anyone got before and after measurements that show a significant change?

Color me skeptical.

Thanks Earl

From a yard sale purchase of a pair of Altec 1203, I ended up with some troublesome 807s and these d130fs (which I discovered after getting the 1203s home and removing their backs). Luckily, I didn’t pay too much, but I’ve spent a lot of time chasing problems.

One of the cones is original and slightly abused, the other is a Waldom aftermarket cone.

I think that I’ll have to write these off. On eBay there’s a recone kit for $150. There’s also a recone service for $175 + shipping. And a remag would need to be done by yet another service $15-30 ? (@ GPA) + shipping. It could easily run $250 per driver, with no guarantees. I just saw that PE offers a speaker reconing service…from their online calculator...$125 + shipping. (I doubt that they can remag, so that would be extra). So again, at least $200+ per driver. And all of the above use aftermarket cones.

It may be better to order a new JBL 2226 for $330 at PE with free shipping and a six-week return policy [ Or try the B&C 15” ].

I would not use aftermarket recones or diaphagms for Altec or JBLs for obvious reasons. Yes, I consider the GPA recones and diaphragms = OEM. There are fewer and fewer JBL recone kits availible now, so this is not even an option anymore for many of the JBL vintage line.

Just for kicks, what does a new 416 woofer from GPA cost? How about a 902 HF driver?

My functional currency is USD.

Thx....

Quote:

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Originally Posted by robertbartsch

Just for kicks, what does a new 416 woofer from GPA cost? How about a 902 HF driver?

My functional currency is USD.

Thx....

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416-8c = $240 USD each
902-8a = $202 USD each

:)

I was under the impression that some of the altec woofs need to be remaged from time to time, but some do not. Maybe Alnico vs. ferrite. can anyone clarify?

Also, I just bought 2 new 399's from GPA for $340 each plus shipping.
I got a quote of $360 for new 416B's also plus shipping.

Quote:

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Originally Posted by Marvin

I was under the impression that some of the altec woofs need to be remaged from time to time, but some do not. Maybe Alnico vs. ferrite. can anyone clarify?

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That's the prevailing wisdom ( that all Alnico magnets will benefit from a recharge ).
ie ; Not just Altec woofers, but any transducer using an Alnico magnet can benefit from a recharge .

Unfortunately, ( & apparently ), the stated wisdom doesn't always hold true / which is the genesis behind this thread . It appears the "charge" won't always take ( hold ) .

If you haven't read the complete thread , then I'd suggest that you do it sooner than later .

As a corollary, member "robertbartsch" had a JBL tweeter ( with an alnico magnet ) rendered unusable ( apparently ) by subjecting it to the remagging process. That's another unsolved GPA remag mystery .

Ferrite magnets rarely demag .

<> cheers

Earl:
I never said the JBL tweeters were deemed useless by GPA in a re-mag job. The 2402 re-charge was done without the noses attached. What happened was (1) the mags/cores were discharged, (2) the mags shifted within the cores since the nose cone and nose cone bolt were not in place, (3) the mags/cores were recharged but the mags were out of alignment.

When I got them back, I could not swap in the new frames and install the horns and noses because the mags were not in the right place.

I shipped them back and Bill and they demaged the cores, re-aligned the mags, recharged the mags, and installed the frames and noses.

In all fairness, it seems a tad weird that Bill would re-mag the 416 cores and not check the mag strength before installing the new VC, cones, etc.

I'm I missing anything obvious?

Thanks ! for the clarification Robert . I did use the word "apparently" for a reason .

A detailed response ( like you have given above ) to my question ( back in post 26 ) would have had me paraphrase your experience differently .


cheers >< :)

Is magnet strength testing after a recharge but before a re-cone a standard practice?

Thx...