Altec 411s rebuilt by Bill at GPA

[robertbartsch]

I have a pair of 15" - 411s that I bought from Fleebay and I had them reconed by Bill from GPA recently. Anyway, over at the JBL/Altec Lansing Forum they tell me that these woofers had a flawed design (deep VC, heavy cone, etc.) and most believe they are not worth restoring into a system.

Although I have not used them yet, I did note they have a very LOW efficiency rating of 93DB at 1 watt at 3 feet.

I've owned a VOTT system for +30 years and always admired the super high efficency (96db) and wide dynamic range of Altecs but the 411s don't seem to meet this bill; right?

I remember the Santiagos when they first were issued in the 1970s and they did not sell well as I remember.

Any thoughts on these?

Thx.

[Todd W. White]

The 411, in the right box (sealed, as I recall, about 9 cubic foot), is an EXCELLENT subwoofer!

[bfish]

Yep, that one lone bad review "over there" has been repeated ad nauseum for years now, often by folks that have never even seen a 411, much less listened to or measured one. IIRC, it was based on second-hand reports of the earliest 411s (or maybe even 413s) that had the cloth half-roll surrounds. Those did have problems, but it was shortly fixed with foam surrounds.

[martyh45]

Howdy,

I have been looking for a pair of 411's so if you decide that they are not for you I would be happy to trade for a pair of 416-8Cs Send me a PM if you are interested. Obviously my opinion of them is not quite the same as the guys from the other site.

[robertbartsch]

One interesting point on the 411 cores I purchased from Fleebay and that I supplied to Bill. These had the pleated black goo surrounds that are the hallmark of many other Altec woofers. I'm relatively sure they were factory original cones/surrounds since I discussed this with Bill before the work was done. He confirmed the "correct" surrounds for the 411 are foam half circle. As I recall, he did not remember any 411s with factory folded surrounds but his discription of the cones and spiders were consistent with the 35 year old cores I supplied to him for the rebuild.

I guess the weird part about this is the motors are a ceramic magnet and not alnico units. I would have thought if the early "problem" woofers had the folded surround but the factory changed the surround to a foam unit to cure the problem in later factory runs, that those units would be alnico not ceramic motors.

As I rememberm, the 411s first came out in the early 1970s and the ceramic magnets did not start appearing until the early 80s; right?

[bfish]

411s (and 413s) were introduced as the "Dynamic Force" series in '71. They originally had doped cloth surrounds, but in the same half-roll configuration as foam as seen here;

http://www.lansingheritage.org/image...ome/page19.jpg

They were always ferrite motors as seen here (also '71);

http://www.lansingheritage.org/image...ome/page25.jpg

At the time, they were Altec's only overhung VC, long throw drivers, hence the need for the half-roll surround. The typical pleated surround can't hack the needed Xmax, so any with pleated surrounds were improper recones.

Don't know exactly when the surround switch occurred, but by '75 they were foam;

http://www.lansingheritage.org/image...ome/page15.jpg

[robertbartsch]

Some pictures that I posted of the re-cones on the other cite are below:


Pics of Altec re-cone Great Plains Audio - Lansing Heritage Forums

[Old Guy]

As I remember, the 411s first came out in the early 1970s and the ceramic magnets did not start appearing until the early 80s; right?

Nope...not at all. I have ceramic magnet speakers from WAY before the 80's.

421's have always been ceramic. So have 411's.

Alnico got expensive due to a serious increase in price of Cobalt. So everybody switched their Alnicos to Ferrite (ceramic).

[robertbartsch]

...So the motors, frames, voice coils on all the 411s did not change during the entire production period and the only factory "inovation" was moving to a foam surround Vs, the early pleated and doped surround?

I remember Bill telling me he had to build the two voice coils to spec from scratch since he did not get many 411 re-builds. He also had to back order some large caps for the 4" VCs as I remember, so they must be fairly rare, I suppose.

Thx.

[Panomaniac]

Yep, there are not many 411's around, but those who hear them, love them.
With the ease of solid state power in the bass these days - why not use them?

If we could get mr. manzanita to chime in, he'd tell you about the 411's and pipe organ music. =)