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  1. #1
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    Altec 817 / 817A cabinet plans ?

    I am halfway into building a pair of 817, my drivers are 416 8A. I have seen different plans but none is complete with all dimensions. Is there different cabinets for the 416 vs 515 ?
    Is there anyone with a complete drawing ? the size of the opening at the speakers and reflex holes is a bit confusing... please help !

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    Senior Member RMC's Avatar
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    Welcome to LH.

    I have the plans and the two versions of the 817 spec sheet. I don't have time right now, i will be back later tonight.

    Richard
    POWERED BY: QSC, Ashly, Tascam, Rolls Mosfet, NAD, and Crest Audio

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    What about connecting the woofers in series instead of paralell? Since this is a high efficiency cabinet it shouldn't require a lot of power to make noise, plus the cost of Watts is low. You need to match the LF/HF levels anyway.

    6 DB for the low-pass (woofers) or on the high-pass side (horn) or for both sides?? Not clear to me the way its written. Assuming for both sides, the most critical would be the high-pass (HF) because of horn protection reasons. You would have to shift the xo frequency higher, like 1 khz, to have comparable CD protection.

    Then the question becomes can the woofers meet properly the HF at 1 khz? According to Eargle a 15" can be taken to 1 khz with a DI 10 db. So a more directional driver, however the LF horn cab is already directional anyway, so some more or less might not spoil the sauce.

    Richard
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    This is the official Altec 817 plans.

    ALTEC 817 PLANS .pdf

    Unfortunately the speaker mounting board info on the drawings has somewhat faded away, but the rest seems ok to read. Maybe the size of the speaker openings are on that mounting board info but its not clear for sure.

    Some cabinet designs can be used with the same driver and for others its a different matter. Sometimes older Altec woofer spec sheets indicated in which cabinet(s) the driver would be a good fit physically and acoustically (See example only on the picture).

    Richard

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    yes, both sides 6dB slope but you are right, maybe to much HF is coming out of the 416 to keep the 288 safe ? I think 1000Hz would be waste of horn size
    I have some alternatives for amps but I will start with LEAK TL12 at 12W . I have not yet tried biamp with passive filter but I feel it has to be identical amplifiers. I have tried electronic crossover but it all fell apart no more drama only HiFi.

    I can see different opinions about serial connection and parallel, The impedance curve would look funny with 4 and 16 Ohm but if I use a tube amp it would be less sensitive I suppose ? the bigges part of the power is going to the bass bin and the horn only a fraction with its higher sensitivity ?

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    Thanks ! I miss the size of the side openings, the curved inner parts are already made. I suppose the width of the inner opening are important as well as the bass reflex.

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    It says that 416 is ok for 816, I think 817 is kind of a double 816 ?

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    Timelens,

    I had a look at other older Altec documents i have and didn't see the info you're missing. I guess you will have to figure it out. You can do a LH forum search on the 817 to see if other people might have posted that info.

    I have a similar impression, 416 roughly comparable but for one woofer. However for the 816A cab its the 416-8C driver that is being specified. I don't recall seeing the A and B specified here, but they might be or work anyway.

    Over the years the 416 has evolved from A version (yours), to B and C. Some driver T/S parameters may have changed a little, plus it seems that some tech info had errors that an Altec author corrected.

    Are you thinking about changing cabinet from 817 to 816 or using some 816 info to help complete the 817 project?

    Richard
    POWERED BY: QSC, Ashly, Tascam, Rolls Mosfet, NAD, and Crest Audio

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    Yes,I realize that it will take som time to figure out and measure the crossover, it took me several years to tweak the Edgar/1505. I actually have 600Hz 12dB and I find it working well. I had the Hiraga correction for the multicell but it kind of took the breath of the horn, I have no audiophile words for it, just boring.
    I guess 416 is a different animal than E130 but the crossover to the horn would be the same. I am thinking of borrowing electronic crossover just to find out the crossover point.
    I find it useless running exclusive/expensive/rare triodes and then run it with a dozen of suspect opamps...
    Thanks for input, great help !

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    No, I already have the difficult parts made, the "wings" and it is just the outer box left. I am very focused at 817. I have been reading/asking a lot about 416 but so far my impression is that 416A has a different basket, B the newer basket and C is "not Alnico" ferrites but I am not sure. Different voice coils for more power also but basicly the same.
    The French version has bass reflex opening under the horn as well and it might be possible to recalculate the area.
    The French has an 190 mm mouth width inside the horn and I would really like to know if it is the same at 817, if I get that measurment right the reflex openings will automaticly be correct (I hope) so please look around for a original 817 and measure it ! There is not many 817 around in Sweden.

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    I found one 816 drawing that specified 200 mm mouth width so 190 or 200 ?!
    My plan is to change from Edgarhorns 80Hz to 817 and keeping the Altec 1503, it has the same width as 817 so it will look and sound good. Edgar has a single K130.
    The bass is a pair of Jensen Imperial so 817 does not need to be working too low. I know 515 might be a better choise for 817 but I have four 416 already...
    And yes I have a girlfriend

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    Hi,
    Mine have 200 mm (+/- 2mm) for the mouth and for the vents 70x350mm x 4.
    They have 416-16As. I believe that the 416A were no longer in production when the 817/816 boxes were introduced, hence the lack of a reference.
    Music is emotion.

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    Thanks a lot ! Nice to hear that 416 is working, I will complete the drawing and start looking for material. Unfortunatly we have a increase of wood prices by 400% but it will not stop me. I have great expectations for this speaker...

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    416-8A goes back to 1972 according to the spec sheet date, so Macsic is probably right about the A being discontinued when the cabs were introduced.

    Richard
    POWERED BY: QSC, Ashly, Tascam, Rolls Mosfet, NAD, and Crest Audio

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    Yes, it is probably so, I remember the Onken 360, It is supposed to use 416 8A but worked fine with all 416 even if Hiraga himself svore by 8A ...
    I will start this project now and see and hear how it is like ! Thanks all for helping.

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