New Heathkit AS101 owner - First post.

[voice of the theater]

Thanks, Mike. That brings up an interesting question. I got these speakers from a guy that buys and sells estates. They came from a house that has been closed up for 20+ years. I guess the original owner passed away and his house was closed up until recently when it was sold.

So these speakers haven't had a hard life of use, but sometimes non-use can be worse for some things. There doesn't seem to be any mold or corrosion anywhere. But it would probably be a good idea to remove all the drivers and give them a good look over.

How would I check the magnets? Would they loose their zing more from use, or non-use? Maybe sending them off to Bill for a recharge wouldn't be a bad idea. I know he does that for free with a diaphragm replacement or re-cone, but do you know what he charges a-la-carte? I've read that while GPAs replacement diaphragms are good, they are not exactly the same and might not have that exact "Altec sound". Myth?

I'm in NJ and haven't worked since Sandy paid her visit. As of this morning, my office still had no power. If that's the case tomorrow, I'll pull the drivers and post pics of what I find.

Here's my take on your questions, although there are others here who know more about some of this stuff than me. BTW, I'd love to see the pics you mentioned you're taking of your drivers.

I will always use GPA for any repair work of my Altec drivers but there is some really interesting info on Alnico magnets including their magnetic properties/potential loss of charge etc. here:

Vancouver Audio Speaker Clinic - Magnet recharging

Here are a few things that caught my eye right off the bat:
"Disassembly If an Alnico magnet structure is opened, such as to re-centre a shifted pole-piece, repair a broken throat, or remove a bug-screen, the magnetic field collapses instantly. While this type of damage is not common, ill-advised repairs create very unwelcome problems."

"Pulse loss
Most Alnico compression drivers (JBL LE85, LE175, 375, 2410, 2420, 2440, 2441, Altec 288, 290, 802, 804, 806, 808, Emilar EA-175, TAD 2001, 4001, Goto Unit, etc) have tall magnets, short voice coils, and modest power inputs, so do not suffer degaussing. Those compression drivers with low aspect ratio magnets, especially if used <500Hz (Vitavox S2, University ID series, Klipsch K-55-V, Electrovoice 1823M etc) can suffer flux loss, and will benefit from remagnetization. "

Based on this info, I think your 806 drivers are probably fine as far as their magnetic charge--especially if they not only sound great but also sound identical to each other in A/B listening tests.....

"Pulse loss

For example: Low frequency drivers with 4-inch voice coils (JBL D120, D130, D140, LE15, 2205, 2215, 2231, Gauss, or TAD drivers) can lose 2~3dB, becoming 'dull' or 'slow' sounding, unless they have been grossly abused, in which case they more and sound dreadful. Drivers with short Alnico slugs and 3-inch voice coils, (JBL 2213, 123A, etc) are effected more severely, so typically show 3dB sensitivity loss, while small alnico woofers (JBL 116A, 125A, 127A etc) are commonly 4dB down after quite modest use. Conversely, speakers with higher coercivity ( taller Alnico slugs) and short voice coils, such as Tannoy dual concentrics, Altec and EV woofers, rarely suffer unless they have been badly abused."

Of course I'd never take this info as a guarantee that my Altec woofers haven't lost any of their magnetic charge, but it's interesting that many Altec woofers can be less vulnerable to this problem than many other woofers that are listed above.

To specifically answer your question, putting too much power through Alnico woofers (particularly some of the ones listed above) can cause them to lose some of their charge, I've also read somewhere that dropping them can have a similar effect. I don't recommend you drop them on the floor from a height of more than 100 feet (kidding).

In all seriousness, I've never had any of my 416 woofers tested for their magnetic charge. I've been fortunate to buy them all from audiophiles who knew enough not to try to put 300 watts through them or to drop them on the floor! I've owned 416z woofers (16 ohm), 416-8A woofers (in my AS 101's), and 416-8B woofers (in my Model 19's), and they've all sounded phenomenal. Also, when I've done A/B comparisons between a pair of 416-8A woofers for example (in their cabinets), they've sounded identical which makes me think there's an increased likelihood they're intact if they both sound not only identical to each other, but both sound incredibly clean and powerful with not only deep bass, but nice midrange as well. I've read that with woofers that are more prone to this type of loss of magnetism (like some of the more vulnerable woofers listed above), when they lose their charge it mainly effects the upper portion of their frequency response i.e. midrange..... So, I've never had a pair measured but of course it wouldn't hurt to have Bill measure them--there are stories here of people who definitely needed their Altec alnico woofers re-magnetized--most likely they were abused (way too much power or dropped) by previous owners...... Of course if you decide to do this, pack them securely because they are much more likely to be dropped by a Fedex employee (and suffer the resulting loss of magnetism) than they were when they were in their cabinets! There are ways of measuring parameters of your woofers (at home, by yourself) that could give you solid clues as to whether or not they've lost some of their "zip". If you've got suspicions about their condition, this would likely be the best way to start your investigation. I've never had to do it, but there are definitely some experts on that type of thing here on our forum.....

Doesn't hurt to check your diaphragms as long as you are proficient at removing them, cleaning the "gap", and re-installing them without damage. It's not that hard to do this safely with smaller format h.f. drivers like your 806's (and my 802's and 902's). Here's some information regarding that procedure : http://www.greatplainsaudio.com/SmDrvrDiaRpl.pdf

I've read that while GPAs replacement diaphragms are good, they are not exactly the same and might not have that exact "Altec sound". Myth?

GPA (former Altec employees) uses authentic vintage Altec designs and tooling. While a brand new diaphragm may not sound identical to a 40 year old diaphragm, of course keep in mind that a 40 year old diaphragm also may not sound like it did when it was new. Your 806-8A h.f. driver takes a 34647 diaphragm. A GPA 34647 will IMHO have the "Altec sound" that the original diaphragm had, and depending on the condition of your diaphragms, may be a nice upgrade in sound quality. Certain original vintage Altec diaphragms aren't currently manufactured by GPA. In this case, substituting a different model # diaphragm for the original will likely result in some degree of change in the "Altec sound", but fortunately the proper replacements are available from GPA for your h.f. drivers if you end up needing them......