Continuum Build

Discussion in 'DIY Corner - Tips & Techniques' started by MrBoat, Jul 4, 2017.

  1. MrBoat Audioholic General

    MrBoat
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    Aurum Cantus AC130-F-1 5.25" woofer.
    [​IMG]

    Along with the Dayton RS28A-4 1.125" tweeter.
    [​IMG]

    I like the look of the cone on the woofer. It has a look similar to graphite. That's also how I would describe the color of it.
    Last edited: Jul 9, 2017
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  2. Pogre Audioholic Samurai

    Pogre
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    You're cruising right along boat! Looking good.
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  3. Johnny2Bad Full Audioholic

    Johnny2Bad
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    That's a pretty thick piece of MDF you're using for the crossover, which might be part of the reason for your frustration. I suggest Masonite next time; stiff, reasonably easy to work, and much thinner.

    Pegboard is OK but just, it's a very lightly pressed material that doesn't have much density. Easy to use, but maybe not ideal once it gets inside the speaker and is subject to pressure forces. The holes would help, but I feel it flexes too much.

    3M makes hot glues and other adhesives that are electronics-safe. Epoxies are fine but a bit permanent. Ordinary hot glues, adhesives and RTVs may not be electronics safe and may lead to corrosion in the future.

    Your build is well thought out and your woodwork is more than adequate. Good luck to you, hopefully it meets your goals when finished.
    Last edited: Jul 10, 2017
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  4. MrBoat Audioholic General

    MrBoat
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    The MDF for the crossover came with the kit from Menicsus. It's 1/4". I think that's probably a good choice more for holding up to the hardware it's fastened to the cabinet with and not breaking being handled by who knows what the bulk of the general public might subject it to.

    Adhesives (even hide glue, urea formaldehyde/resorcinol) and materials are something I have a lot of experience with. The hot glue is more of a shim for vibrations than an actual adhesive in this case, since the leads are thru the board acting as a staple, with zip ties on the heavier parts. Mostly I just don't like the blowout from the drill bit on MDF leaving that ugly burr on the back side, where even a razor sharp countersink only makes it bigger. I've since thought of ways to mitigate that in the future.
  5. MrBoat Audioholic General

    MrBoat
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    Dry fit all of the components, baffles etc. Everything worked out great. I need to loosen up the woofer mounting screws a bit since I used an exact size letter drill to the screws. I just need to center the woofers a little better is all, being that they are thru-bolted with machine screws and nylock nuts. Still not sure if I will keep these baffles with veneer and faux paint/grain the driver recess to match the veneer or just make hardwood baffles for them. Again, depending on how good they sound will decide the level of finish detail. Either way, I left the tweeter recess approx. 1/40" shallow to allow for the thickness of veneer, and also didn't countersink the cabinet screw holes all the way as of yet.

    They came out pretty tidy and dead-nuts square.
    [​IMG]

    I used a more conventional screw pattern for the removable backs. I will likely mount the crossovers there.
    [​IMG]

    I have to say, Meniscus puts together a pretty decent kit. I liked the fact that they included 1 extra of each screw. That is telling that builders assemble these kits. Someone like me, really appreciates those extras.

    I have to say, there is a lot of extra work with the details of this kit. Mostly the battens that hold the baffles/backs on, and the multitude of screws and associated drilling. Thankfully, I have a drill press, or I'd still be at it. I do actually drill pretty straight with the cordless because I use one a lot every day but this would be pushing it.
    Last edited: Jul 11, 2017
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  6. Swerd Audioholic Ninja

    Swerd
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    Thanks for all the build photos. Your work, as always, is worth seeing.

    Those cabinets are small, so mounting the crossover boards on the removable backs is a good idea. Keep them as far away as possible from the large woofer magnet so it doesn't affect those inductor coils. Behind the tweeters is probably your only choice.

    What is the item in your photo to the right of the air-core inductor coil? It looks like a capacitor jacketed by an aluminum heat sink.
    [​IMG]
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  7. MrBoat Audioholic General

    MrBoat
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    It's a resistor. I have seen photos of other continuum builds and it had a different resistor. Perhaps they were out of the exact value and sent this one, I don't know. In some of the older crossovers, two caps adding up to the same value as these single units were used etc. I was wondering about if heat was an issue but there is no mention of it or cautions regarding insulation contact with the board.
  8. MrBoat Audioholic General

    MrBoat
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    I discovered I had a brand new Lawrence, single flute countersink (the kind with the hole thru it)stashed and it cuts countersinks in the MDF quite well.
  9. Swerd Audioholic Ninja

    Swerd
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    I've never seen a resistor like that for crossover use in audio.

    I'm not aware of heat being an issue for caps, only for resistors. I've seen some builders carefully mount resistors over some small strips of wood (cut matchsticks) that elevate the resistor like rails over railroad ties. I've never done that. If power handling and heat dissipation is an issue, it would be better to use two resistors in parallel instead of one.

    So… How do the Continuums sound?
  10. MrBoat Audioholic General

    MrBoat
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    Perhaps Meniscus couldn't source the correct resistor, or maybe size was an issue being the lead from the other resistor next to it is just barely long enough for a point to point wiring as is. A longer resistor like the green one next to it would have had to have an additional wire added to make the connection. Maybe the standard resistor just gets warm and they are trying to stupid proof it a little being these are kits sold to the unwashed masses for the most part. No telling. Either way, I will check to see how warm it gets but I have a feeling it won't. For all I know, they could have gotten an incredible bulk deal on these and are trying to use them up.

    I haven't fired them up yet. This was just to get the drivers fit and all the fastener holes drilled, check clearances etc. This was one of the most tedious portions of the build so I wanted to get that out of the way. I still have to add damping etc. I will likely fire them up just running the crossovers outside the box before I go to the trouble of permanently mounting everything.

    These speakers look small but they have some heft to them.
  11. MrBoat Audioholic General

    MrBoat
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    Ok. . . . these things sound really-really good. :D

    I ended up mounting the crossover sideways up in the top, as a previous poster suggested. This puts it furthest away from the woofer. I mounted it to the inside of the battens as this allows for the 3/4" foam to still cover the entire back and behind the crossover since the battens are also 3/4".
    [​IMG]

    Not going to go into a bunch of predictable, audio trend-speak on how they sound. All I can say is, these are a fantastic pair of little speakers, especially along with the 12" sub. Jeff Bagby's description is spot on. If I were to wrap it up in a simple explanation, these speakers fall into that realm of, if something sounds better than these little dudes, pound-for-pound, you wouldn't/shouldn't care.
    Last edited: Jul 14, 2017
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  12. MrBoat Audioholic General

    MrBoat
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    This is the veneer I chose for the cabinets. It's a birch burl. I didn't want to go dark colors on such small boxes. I have an idea about letting in a birch blank in where the woofer is and re-routing that part in solid, laminated together pieces of wood so that I don't have to blend MDF with the veneer in that transition area.
    The returns where the baffles go, I can do a faux bois trick and get away with it there.
    [​IMG]
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  13. MrBoat Audioholic General

    MrBoat
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    Seems I got lucky ordering this kit when I did. I see now that the kit is "out of stock" at meniscus due to lack of availability of the Dayton RS28A-4 tweeter and Parts Express is no longer listing this tweeter, either.
  14. slipperybidness Audioholic Spartan

    slipperybidness
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    @MrBoat

    Of course they sound good to you after all that work. Obviously, we can't trust your biased opinion!
    :rolleyes::D:D:D

    Haha. Looking good, and considering the pedigree, I'm sure that they are nice speakers.
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  15. MrBoat Audioholic General

    MrBoat
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    I was hoping they would sound this good after all that work. I had a feeling they would though. But then I did not know how I would fare with a reference monitor for recreational listening.
  16. shadyJ Audioholic Ninja

    shadyJ
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    Do you know if there are any measurements for this speaker?
  17. MrBoat Audioholic General

    MrBoat
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    • Informative Informative x 1
  18. MrBoat Audioholic General

    MrBoat
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    When I search Rogers LS3/5a frequency response in google images, I come across a graph that compares the Continuum to the BBC speaker. Since it's been deleted from photobucket for whatever reason, I didn't know if it would be cool to post it here.
  19. shadyJ Audioholic Ninja

    shadyJ
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    Looks like a great speaker, thanks.

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