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Thread: New to the Forum (Altec Model 19 Fan)

  1. #1
    blankster
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    New to the Forum (Altec Model 19 Fan)

    After finally enjoying an evening with my system (no kids/wife home), I thought I'd join the forum. In 1977 I bought 2 Altec Model 19s for what was then a stereo system. But with the advent of home theater and after buying and selling several different rear channel speakers I bought 2 additional model 19s for the rears. I'm running several Adcom amps at 300RMS per channel. I must say, I'm in heaven.. If only I could ditch the wife's china cabinet in the living room. It would be a great place to put a JBL Paragon.

  2. #2
    Webmaster Don McRitchie's Avatar
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    Hi Blankster

    Welcome to our forum. There are a few Model 19 owners lurking on this board. I am the newest member of that group since I just picked up a pair last week. Unfortunately, both compression drivers were non functioning so I can't listen to them. Replacement diaphragms won't be here for another week, so I have to learn patience. In the interim, I am oiling them up with tung oil to bring back the finish that 25 years of inattention has dried out. Other than that, the cabinents are perfect, without a scratch or ding that I can see anywhere. The system even came with the foam horn surrounds in tact. However, they didn't stay that way long. I had to remove them to get at the compression drivers to find out what was wrong. In the process, the surrounds crumbled into pieces. Fortunately, I have a line on a replacement set that may be here as early as next week.

    I just checked the date codes, and they were made in February, 1978. Therefore they have the 416-8B and 802-8G driver complement. I was concerned about the fact that they are Alnico drivers which are susceptable to partial demagnetization with overpowering. However, the history on this system that I was told was that they were never played much above background music levels and spent the last twenty years unused. I have independent verification that this was the case so once the new diaphragms are in place, I'm hopeful that they should perform to factory specs. Right now, I'm trying to track down the best means of damping the 811 horns which are known to have a ringing problem that tends to make the midrange response uneven.
    Regards

    Don McRitchie

  3. #3
    rvito
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    Don, Where do you find the date codes on the 19's? Thanks, Rich

  4. #4
    Webmaster Don McRitchie's Avatar
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    It's on the terminal plate underneath the speaker where you connect the speaker wires. It's just a simple stamp of five digits grouped into three sets that represent month, day and year. Mine says 2 13 78.
    Regards

    Don McRitchie

  5. #5
    rvito
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    Don,I checked the horn Driver that I had removed and I cannot find that type of Number. The only group of Numbers I can find are on the label of the driver-27-03-033952. Would the date code be located on the Woofer? Thanks, Rich

  6. #6
    Webmaster Don McRitchie's Avatar
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    It's not on the driver, it's on the terminal plate underneath the cabinet where the speaker wires are connected as shown here:
    Attached Images Attached Images  
    Regards

    Don McRitchie

  7. #7
    Webmaster Don McRitchie's Avatar
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    And here it is in close-up.
    Attached Images Attached Images  
    Regards

    Don McRitchie

  8. #8
    blankster
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    I had one of my HF drivers rebuilt by Great Plains Audio. He did an excellent job. He also did some work for a friend of mine (reconed the 416-B'). Regarding the loss of magnetic power, I'm not familure with that. What causes it? What is the effect of the problem? I've owned mine since and never used less than a 300W/per channel amp.

  9. #9
    rvito
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    Thanks for the info. Why in the world did they put the Terminals on the bottom of the speakers for? Date code is 03-01-77 what horn driver might I have? Thanks, Rich

  10. #10
    Webmaster Don McRitchie's Avatar
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    To Rich

    You should have the same driver complement as me - 416-8B woofer and 802-8G compression driver. These are both Alnico magnet drivers. Starting some time in 1979, Altec replaced the woofer with the ferrite magnet 416-8C. Later still, around 1980 or 1981, the compression driver was replaced with the ferrite magnet 902-8A.

    To Blankster, Alnico magnets, while having many beneficial qualities, have the lowest coercivity of any magnetic material used in loudspeakers. What this means, is that they are easy to demagnetize when exposed to high current levels - such as a high power signal sent through the voice coil.

    It is entirely possible to demagnetize an Alnico driver in a home environment. A high power pulse of less than half a second is enough cause permanent loss. A common culprit was the power on "whompf" of older amps. The phenomenon was common enough that my web partner has never measured a Alnico driver that still held its factory spec magnetic energy and he's measured dozens. Virtually all of these were from pro use, but I would suspect a high percentage of home speakers also have suffered some loss.

    The symptoms in a bass driver are a dip in response above 100hz. Below that frequency, the reflex tuning governs and the response remains roughly the same. In a compression driver, it results in a rolled off HF response.

    The magnets can be restored by being re-energized, however, they have to be dismantled in the process. Great Plains does this as a matter of course for every driver they recone. If you ever blow a driver, it is a guarantee that there has been permanent magnetic energy loss. That is why Great Plains re-energizes drivers as a part of the recone process.
    Regards

    Don McRitchie

  11. #11
    jbl
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    Hi Don,
    Looking at your picture, you are close to shorting the speaker wire. It was a bad design decision by Altec to have the speaker wire connected from the bottom considering the weight of the cabinets.

    Ron

  12. #12
    Webmaster Don McRitchie's Avatar
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    No argument there. I've since replaced that speaker wire.
    Regards

    Don McRitchie

  13. #13
    Todd W. White
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    Hi Guys,

    Altec put those terminal connectors on the bottom of the Models 14, 19, the Stonehenge series, and probably some others I can't recall right now because the backs of these systems were finished - the idea was you didn't have to put them backs to the wall: you could put them anywhere in the room, and they'd look good.

    The connectors are also WAY too small!

    THE IDEA WAS WELL-INTENDED, BUT, IMHO, IT WAS STUPID!!!!

    The ICONIC systems are similarly finished, but the purchaser has a choice where he wants us to put the terminals.

  14. #14
    Webmaster Don McRitchie's Avatar
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    Todd

    Did that have anything to do with the Japanese market? The reason I ask is that I just got the most recent issue of Stereo Sound Japan which is the 150th edition. In celebration, they have thumbnail pictures of every cover from all 149 previous issues that go back to 1967. What surpised me was the number of covers devoted to Altec speakers. I'm guessing that Altec was making a concerted effort sell into that market, particularly in the 1970's. The Japanese market seems to equate visual aesthetics with overall quality so I can see where an unfinished speaker back would be considered of inferior quality, even if it was never seen.

    The finished back seems superfluous in North America. Even the bottoms of the 19's are veneered and this seems entirely silly. The only market where this might have some appeal would be in Japan.
    Regards

    Don McRitchie

  15. #15
    Todd W. White
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    Hi Don,

    Well, being a woodworker (amateur), and having a close friend who builds our cabinets, I can tell you that it is much less hassle to stock and build your cabinets out of the same material - hence the veneered bottoms.

    As for the marketing - I am sure that the Japanese market had something to do with it, as you say. I also remember that there was a trend in living room designs here in the USA in those days to get things out in the open...

    These things combined amde for the decision to build them that way.

    (I still hate where they put the input terminals!)

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