Altec Santiago "A" to "B" surgery (perhaps)?

[mhardy6647]

http://www.lansingheritage.org/html/...akers/878a.htm

Ok, here's the deal. I have acquired a pair of Altec 878A Santiagos from a local hifi friend, who had in turn acquired them from their original owner here in MA for a very reasonable (virtually cheap) sum. They are in good shape down to the original grilles (some scuffs and water marks, but not bad at all). As it turns out, there is one flaw: One woofer is the orignal 413-8 (3" VC), but the other has been replaced with (to quote my friend) "a Speakerlab knock-off" (of unknown provenance and T/S parameters, I would add).

Thanks to another local hifi guru, there is an opportunity to acquire a pair of Altec 411-8A woofers. This (IIRC) is the woofer used in the 878B version of the Santiagos, with a 4" VC and (presumably) more efficient (and perhaps differing in other ways as well, I don't know).

So here is my simple/simple-minded question. If I were to acquire the 411-8A woofers, can the 878A Santiagos be "converted" to 878B via the construction of a new crossover?

If so... can someone point me to an appropriate crossover design to integrate the 411-8A with whatever driver (I haven't looked) is on the 811B in the Santiago?

I hope that this question isn't too naive!

For the record (and FWIW) the main speakers at my house are a pair of 846A Valencias.

Thanks for your attention!

[Earl K]

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[robertbartsch]

The sensativity ratings for the 411 and 416s are very different. In addition, the 411 is designed for a sealed enclosure and the 416s are designed for a ported box.

I would go with 416s not 411s.

[mhardy6647]

The sensativity ratings for the 411 and 416s are very different. In addition, the 411 is designed for a sealed enclosure and the 416s are designed for a ported box.

I would go with 416s not 411s.

The box is sealed. The question is XO design for 411 vs. 413. I've got a pair of Valencias... ;-)

[grumpy]

It would be good to read the chart Earl posted.
(N801-8A)

[mhardy6647]

It would be good to read the chart Earl posted.
(N801-8A)

Fair enough. I had seen the chart when I perused the site last week (although Earl has helped me here before and I certainly appreciate his reminder, since I didn't specifically say what research I'd done already). The XOs are identical in the A and B, then, despite the different woofers? I thought there was some sort of contour network also employed on these systems?

Has anyone here (heh) A-B'd the A and B versions?

EDIT: I do appreciate the advice; I really don't know much about the Altec Lansing legacy (other than that I like the sound of the Altec drivers and horns, bigger and small(er)).

EDIT^2: On the parts list, what does "Comp." mean?

[Zilch]

On the parts list, what does "Comp." mean?

Contour network, including a Zobel for the woofer.

Search "30904" here and on AK.

You'll also find my adjustable version, lifted from Model 19....

[mhardy6647]

ah, light begins to dawn. The only difference to accommodate the woofers is a contour network on the woofer (the tweeter networks are derselben, the same)?

but the 413 contour network is "30905" and the 411 is "32321"? What's the "30904"?

And the Nineteen is ported...

Uh-oh, the light's dimming again :-P

Thanks, Zilch!

[Earl K]

Comp. ( as used within the "pink" Altec reference charts , means ) "equivalent component number" ( IMO ) .

- Buy the 411-8as , stick them in, listen for some time & take it from there .

- 411s are easy to get rid of , if ultimately that's the road chosen .

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[mhardy6647]

That's concrete advice! Thanks! :-)

I do appreciate the expertise... that's why I come here when the Altec/JBL goin' gets tough for me (which happens pretty quickly in my case).

Happy Thanksgiving, y'all (at least all y'all in the US)!

mrh

Comp. ( as used within the "pink" Altec reference charts , means ) "equivalent component number" ( IMO ) .

- Buy the 411-8as , stick them in, listen for some time & take it from there .

- 411s are easy to get rid of , if ultimately that's the road chosen .

><

[mhardy6647]

Courtesy of Don McR. (on the subject of the 411 woofers):

"You can tell the pioneers by the arrows sticking out of their backs."

http://audioheritage.org/vbulletin/s...4&postcount=10