3000 G Horns

[seville]

One of the tweeters on my Seville speakers doesn't play as strong as the other.
I removed them from the cabinets and played them, one at the time, connected to the same crossover. The difference persisted.

I learned from the Forum how fragile these horns are, and that there is only one guy in CA who bring them back to live if they are toast.

In the meantime and since they both still play, any information about what might be the problem (or ways to test them to find out) would be very appreciated.

[Steve Schell]

In your reading you probably found out that the diaphragms in these units were derived from a Western Electric dynamic microphone diaphragm. They are sweet sounding tweeters but notoriously fragile.

You might start by measuring the DC resistance of both tweeters. If the one with low output measures higher DCR than the other one it may be because one of the lead out solder connections has gone high resistance due to corrosion. These voice coils use aluminum wire which is notoriously difficult to solder to. If this is the case then carefully reflowing the solder joints may fix it. If the low output tweeter has developed some shorted turns (would measure lower DCR) then it may be toast and it is time to call Bill Hayes.

Good luck with this, seville.

[seville]

Thanks a lot Steve,
I did measure the DC resistance and they both read 11 ohm. Any thoughts?

[Steve Schell]

Well it sounds as though both voice coils are intact and correct. If the output of one of the tweeters is lower then something is keeping the diaphragm from moving like the other one. My guesses would be either a partial separation of voice coil bobbin from the diaphragm or some physical obstruction (hunk of junk) in the voice coil gap. It will require disassembling the driver to diagnose. I've never had one of these apart so I don't know how dodgy an operation this will be.

[seville]

Thanks again Steve. Last night I did disassemble the driver. It's not a very dodgy operation to a certain point. The diaphragm appears to be in good shape and there was nothing (outside) keeping it from moving. To see the voice coil, I would have to release two hair-thin (aluminum?) wires stemming from each side of the diaphragm and soldered to the connectors underneath. That's where I stopped. From the openings on the side of the magnet I could see a white cloth insulated wire, loosely wound 4 or 5 loops around the center of the structure, but no view of the voice coil gap. To get to it, the diaphragm would have to be removed, the two hair-thin wires disconnected, which I wouldn't dare to do. The odds of some junk being lodged in the gap are rather slim since the driver is completely enclosed. I would guess that a partial separation of the voice coil from the diaphragm is more likely, so the horn will have to take a trip out west at some point. In the meantime, I need to refinish the cabinets, fix one of the grilles and persuade my wife to admit the Sevilles into the living room. A lot of work ahead. Thanks again for all,
NC

[miklos]

Hello Seville,
I have a defective HF section of a Altec 601, which I would like to fix.
Since you took one apart, could you please tell me the approximate dimensions of the cavity where the driver is mounted. I would like to try to replace that fragile driver with one of the new neodymium dome tweeters. I would like to have an idea about the size I need, before attempt this operation, never did anything like it before.
Thanks Miklos



One of the tweeters on my Seville speakers doesn't play as strong as the other.
I removed them from the cabinets and played them, one at the time, connected to the same crossover. The difference persisted.

I learned from the Forum how fragile these horns are, and that there is only one guy in CA who bring them back to live if they are toast.

In the meantime and since they both still play, any information about what might be the problem (or ways to test them to find out) would be very appreciated.

[Stewburner3]

hello all,
This is my first time on the forum, so apologies for my inexperience.
Bought a huge set of barzilay cabinets including credenza. Had altec badges in corner of each speaker. Dimensions of each speaker aprox.4 1/2'w ×4' h x 2 1/2 deep. Credenza was loaded with dynaco st120, pat4 and dynaco stereo tuner. Teas reel and bang and olufsen table. All of the stuff in the credenza was functional except the pat4 and 120. But the main attraction was the altec walnut monsters. First played them on old tube pioneer amp 15 wpc.... Wow. .incredible. I have other large speakers, first gen cornwalls, and 2nd gen khorns but these altecs are like butter. So couldn't wait to open 'em up. After removing over 30 wood screws and some window putty sealant found a 15" jensen because with bell cover, my heart sank. But continued, all yellow fiberglass insulation professionally installed with criss cross webbing concealing oil can cap crossovers huge rectangular silver items. In the middle of the cabs interior a separate enclosure withnuerous wood screws. Like a true burleque star she made me tremble with anticipation. Behind was a beautiful blue green 755c. Above it a 3000a with green horn.
The other speaker was mirror image but for the jensen15 wasn't a flexair simply lf driver and this one had crinkle paint.
Now I have read you should always replace old caps and that the 3000 tweeters are fragile, Is there any advice on what I should do in respect to maintenance . All of the drivers look like showroom stock. Paid 100.00 for all:applaud:

[gdmoore28]

Hi Stew!

Your first post is a real doozy, I must say. What a discovery you've made.

Honestly, you will get a LOT more information on Altec systems and drivers by posting your questions to the Altec Users Board:

http://www.hostboard.com/forums/f700/altec-users-board.html

or Audio Karma:

http://audiokarma.org/forums/index.php

While this great site is all about JBL, the Altec representation is a good bit lighter. (Though it is hard to beat the Altec Lansing library here.) Both of the above sites have three or four members that are absolute Altec encyclopedias and will be able to answer your questions pronto and with absolute accuracy. (By the way, this site has a couple of Altec experts, as well. Hope they will see your post.)

In the meantime, may be please see photos of the cabinets and components? They sound beautiful. And don't neglect to add photos when you post on the other two sites, as well.

GeeDeeEmm