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Very early Altec 602D

S

stevengerard

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I picked these up over the weekend for next to nothing. Wasn't sure what I had but a quick post on FB made me grab them. I hooked them up to a Kenwood 1400 to make sure I didn't damage them as I read the tweeter is very fragile. They sounded pretty good until I played some Jazz with soprano sax and a lot of high-hat. I disconnected the fullrange and sure enough, no tweeter. I read these are near impossible to rebuild. Is that true?

The cabinets are both stamped 49, which correlates to 1949. Both drivers are coded 391806 - 391=Altec, 8=1948 and 06=6 week
 
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stevengerard said:
I read these are near impossible to rebuild. Is that true?
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Sadly, yes.

The diaphragms were actually built up from a microphone diaphragm.

The one cottage business(Bill Hayes' Micro Mike Labs) that could repair them is now long defunct, and the necessary tooling dispersed.

stevengerard said:
Both drivers are coded 391806 - 391=Altec, 8=1948 and 06=6 week
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1968.

A 1948 Altec would have gray krinkle paint, a paper hinge, a 2 piece split rim basket, and no EIA/RETMA code. The 391 code belonged to Peerless Electrical Co(Altec's transformer division) until 1949 when it was assigned to Altec. 1949 and 1950 Altec drivers were built in Hollywood, and are marked accordingly.

The cabinet is also 1960's

The upside here is that if indeed the tweeter VC's are open, the OP has the equivalent of very nicely preserved 416-8A woofers, just add a commensurate HF element and XO. About as good as it gets for an E-wave project.
 
Too bad the tweeter doesn't work as the rest of the speaker looks like it is in great condition. I did find two pair for sale on ebay but they are crazy expensive. For now I'll look for an appropriate replacement. The cabinet has a perfect spot already cut in above the woofer to mount a separate HF driver.


Altec 602D w tweeter.jpg
 
stevengerard said:
Would these Jensen RP109A horns be a good replacement?
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Probably not a 1st choice to compliment an Altec 416 for most of us. But, they would provide some high end where things are currently very rolled off, and you have them on hand.

With a 13 ohm DCR those are 16 ohm horns. If you use them with the factory N3000 networks, they're going to come in somewhere around 1500hz which is probably a tad low for them while at the same time getting a lot closer to ideal for the woofer. I'd be tempted to try them while being fairly judicious with the volume.

Another consideration might be connecting them parallel with the input using a 1st order filter aiming for a ~6khz knee point while letting the woofer continue to run through the LF section of the N3000.

stevengerard said:
803(?)woofers
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803's would be 16 ohm.

Your woofers are 8 ohm and effectively 416-8A, they offer a lot of hifi potential.
 
bowtie427ss said:
Probably not a 1st choice to compliment an Altec 416 for most of us. But, they would provide some high end where things are currently very rolled off, and you have them on hand.

With a 13 ohm DCR those are 16 ohm horns. If you use them with the factory N3000 networks, they're going to come in somewhere around 1500hz which is probably a tad low for them while at the same time getting a lot closer to ideal for the woofer. I'd be tempted to try them while being fairly judicious with the volume.

Another consideration might be connecting them parallel with the input using a 1st order filter aiming for a ~6khz knee point while letting the woofer continue to run through the LF section of the N3000.


803's would be 16 ohm.

Your woofers are 8 ohm and effectively 416-8A, they offer a lot of hifi potential.
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Wow, you are a wealth of information, thanks. I see there are some modern drivers I could replace them with as well as some Realistic I see that you recommended as good replacements. I might just try what you suggest with the Jensen horns I have while keeping an eye out for the realistic. I don't mind spending a few busks on replacement drivers as I got this pair for basically less than the cost of the cabinet.
 
stevengerard said:
as well as some Realistic I see that you recommended as good replacements.
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When they were plentiful and inexpensive... as a direct replacement for the Heppner horn found in the 890C Bolero.

I suppose that corrected for inflation they're still inexpensive. But, they sure seem a lot less plentiful after a quick ebay search. I saw several pair in completed sales. But, only a single being offered currently.

For the sake of clarity for others that may peruse the thread, we're speaking of the original RadioShack/Realistic 40-1228 die cast tweeter horns made by Foster/Fostex.
 
There's a guy out there that said he could repair the tweeters. I think he wanted $500 apiece so I declined. It's been awhile since I contacted him.

I bet these would sound good.

Pair of Heil AMTs

1775363961446.png
 
Just remembered I have these I was using before I bought my Fostex supertweeters on my A5s. My next iteration of A5 is going to have the above Heils.image.jpg
 
bowtie427ss said:
When they were plentiful and inexpensive... as a direct replacement for the Heppner horn found in the 890C Bolero.

I suppose that corrected for inflation they're still inexpensive. But, they sure seem a lot less plentiful after a quick ebay search. I saw several pair in completed sales. But, only a single being offered currently.

For the sake of clarity for others that may peruse the thread, we're speaking of the original RadioShack/Realistic 40-1228 die cast tweeter horns made by Foster/Fostex.
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There are actually plenty of these 1228s out there it seems, or maybe it was just good timing. Fortunately @MissionX was kind enough to sell me a pair at a very fair price. I already installed one and definitely helped.
 
I removed the interior panel on the cabinet and sure enough there is a s cutout for a horn. I cut a new piece of plywood to allow the installation of the 1228. Now to experiment with rest of the cabinet. I am quite surprised how little dampening material is in each cabinet. Not only that, but under the lower plywood support piece is a rectangular port that is open. I would think these speakers were best suited for a sealed cabinet. Any thoughts on that? Also, should I add more cross-members to make the cabinet more rigid?


Altec cabinet.jpeg
 
stevengerard said:
I am quite surprised how little dampening material is in each cabinet.
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Back in the day, the standard was to damp 3 internal sides. That's generally all that's necessary to stop standing waves. Sometimes, port location and arrangement can require a bit more if there are issues with reflections making it out of the port.
stevengerard said:
but under the lower plywood support piece is a rectangular port that is open.
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Sometimes called a shelf port.
stevengerard said:
...a sealed cabinet. Any thoughts on that?
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Anything but for an 803/416, unless you're trying to make it a subwoofer. Those woofers really want a port.
stevengerard said:
should I add more cross-members to make the cabinet more rigid?
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A front/back brace from the baffle area between the large rectangular opening and woofer opening would be my first step, followed closely by diagonal reinforcing braces on the sides and back.
 
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