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Altec A7 cabinets with no components - what to do?

Discussion in 'Speakers' started by plschles, Oct 13, 2018.

  1. plschles

    plschles AK Subscriber Subscriber

    Messages:
    28
    Location:
    Central Florida
    Hi, I was given a pair of Altec A7 cabinets, with no components. Anyone know where I can purchase these parts? thanks.
     

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  2. bowtie427ss

    bowtie427ss arigato gozaimashita Subscriber

    Messages:
    16,916
    Location:
    Land of Milk & Honey Boo Boo
    Looks like model 825 cabinets. Got a pic of the back of one?

    A7 is is a system of components using small format HF with a few acceptable variations.

    The placement of the horn brace suggests these had 511 horns on them which would indicate some version of A7-500, or sound reinforcement model 1236.

    Ebay is by far the largest source of regularly available vintage components.

    Some components show up here in AK Bartertown from time to time.

    New components at an ever increasing premium can be purchased from Great Plains Audio.

    Of course, there are no laws that say you MUST load them with Altec components.

    Any halfway decent 15 inch bass driver with a fairly low Qts(.3 or less) will play very well in those boxes. Just be aware that the cabinet is primarily a mid bass horn and functions as a bass reflex system from `100hz down to somewhere in the 50hz region. There is a good bit of acoustic gain from the horn across it's BW roughly 100hz - 1khz, and that will augment the mid forward nature of specifically voiced MI drivers.
     
    Last edited: Oct 13, 2018
    Zonker92 likes this.
  3. plschles

    plschles AK Subscriber Subscriber

    Messages:
    28
    Location:
    Central Florida
    thanks
     
  4. Thierry

    Thierry Tape with a passion

    Messages:
    554
    Location:
    Paris, France
    Last edited: Oct 14, 2018
  5. gdmoore28

    gdmoore28 Super Member

    Messages:
    2,815
    Location:
    Central Arkansas
    Tom, could you give him a listing of the exact woofers/horns/drivers/crossovers that he needs to get his Altecs back up to specs? It might be very helpful if he doesn't already have a listing of the part numbers.

    Would also be interesting to see what alternative components you might suggest if budgeting is a big concern

    GeeDeeEmm
     
    darkblue94 likes this.
  6. Johnny_Law

    Johnny_Law AK Member Subscriber

    Messages:
    1,934
    Location:
    North Bay, NorCal
    Congrats those look like they are in great shape. And shoot, here I am with A7 components in DIY cabs on the other end of the country. :p
     

     

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  7. ragtopolds6

    ragtopolds6 Active Member

    Messages:
    181
    Location:
    butler pa
    gary fisher speakers butler pa...legand
     
  8. bluesky

    bluesky Addicted Member

    Messages:
    7,524
    Super nice cabs!!!!!!
     
  9. bowtie427ss

    bowtie427ss arigato gozaimashita Subscriber

    Messages:
    16,916
    Location:
    Land of Milk & Honey Boo Boo
    Without the OP's participation, we're pretty much just going to look like a bunch of monkeys humping a football.

    Where is the OP going to use them?

    What's he going to drive them with?

    What's the budget?

    Making them "Altecs" again is gonna minimally cost the best part of a grand, done right.

    We need to see the backs unless the OP is willing to hack them up for a recommended crossover.

    Depending on what they left the factory as, they could have just a single small hole where an L-pad shaft poked thru, they could have a square cutout for the N501/N801 chassis, or they could have a larger rectangular opening for the 771 bi-amplifier, sometimes with a wooden adapter plate to accept the N501/N801.

    Personally, i wouldn't waste my time with any of the early networks used in the A7. I'd go for N1201, N1285, or scratch build. But, those will not fit any factory opening that his midrange vintage cabinets might have came with. They would require cutting, modifying, or external mounting.

    A7 production began with 803A woofers, ended with ferrite 515's, and would include every iteration of 416 woofer.

    There were probably at least 10 cataloged versions of the A7. They all use different combinations of components. What the OP's cabinets are cut for will greatly help narrow down what might have been in them originally, and whether they were 8 or 16 ohm versions, or if they were ever A7's to begin with.

    From the available information the OP has given they could have just as easily been 1236's which share little more than the cabinet with an A7 of any variety.

    Any woofer/bass driver with a Qts below .30 will work, most quite well. Crossover and horn/driver choices will be somewhat dependent on the listening space and preferences. If they're going to be enjoyed from a fixed listening position, then they can be crossed a good deal higher since beaming and narrowing dispersion won't be an issue in that scenario.

    If the OP wants to fill a room with intelligible speech, then a lower crossover point needs to be used which will require a horn that both provides an appropriate acoustic load for the driver, and pattern control to suit relatively even coverage of the room. This will also require a compression driver capable of the lower crossover point which in many cases will mean compromising VHF response and economy.

    OP, where are you?
     
    Zonker92 likes this.
  10. gdmoore28

    gdmoore28 Super Member

    Messages:
    2,815
    Location:
    Central Arkansas
    That's what I was wondering . . . come forth, Plschles!

    The wall-hangers in his room give some indication that he's done woodworking recently, so maybe he has a bit of a head start when it comes to shredding wood, if needed.

    GeeDeeEmm
     
  11. Blue Shadow

    Blue Shadow I gotta get me a new title

    Messages:
    21,030
    Location:
    SE PA
    Time to check into this thread and help those that are trying to answer your questions. Even though by now you have ordered everything you need, these guys are wanting to build an A7 based on your boxes in their discussions. A few answers and pictures will make them happy. We like pictures.
     

     

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  12. plschles

    plschles AK Subscriber Subscriber

    Messages:
    28
    Location:
    Central Florida
    I think I will be selling these and posting in BT. Thx.
     
  13. Goggle1824

    Goggle1824 AK Subscriber Subscriber

    Messages:
    517
    Location:
    Twin Cities, USA
    Doh!

    Always an option as well...
     

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