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  • #16
    Originally posted by Chris Roemer View Post
    Too late now (prob'ly), but in general, 2 woofers playing diff. signals (stereo) should each have their own vented space. A driver (driven off air pressure - even sound) will generate voltage as it moves - much like a microphone. Looks great though. Same volume and tuning I used w/my "femtoneo" design (tweeterless). What the tweets add (mainly) is some HF dispersion, probably giving a much more "open" sound.
    Did you do a write up on the "femtoneo" Chris? sounds quite interesting.

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    • #17
      (that's just what I ended up calling my White Bricks - once the W3 woofers were replaced)
      Nano Neos - used the ND105-4 in a 2-way (below 40Hz in about 0.30cf)
      NtN - MTM vers. of the Nano Neos (0.6cf)
      PicoNeo - just an AURA NS3 (ND90-8 equiv. in 0.15cf) F3<50?
      femtoneo - ND65-8 in about 0.055cf - the -8 has a nicer looking top octave (and a little BSC) in its FR plot. 60 easily.

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      • #18
        Thanks guys... I've learned so much in 2 years, I am really pleased with the finished look but I think I would do the internals (both box configuration and electronics) much differently now.

        I've been messing around with 5V amps for boomboxes lately; the chipamps (PAM8406 for example) are cheap and you can run the whole thing from 1 lithium cell. For desk listening it's usually enough power.

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        • #19
          Originally posted by jdhill View Post
          Thanks guys... I've learned so much in 2 years, I am really pleased with the finished look but I think I would do the internals (both box configuration and electronics) much differently now.

          I've been messing around with 5V amps for boomboxes lately; the chipamps (PAM8406 for example) are cheap and you can run the whole thing from 1 lithium cell. For desk listening it's usually enough power.
          What would you do differently with the internals?

          I'm starting my next one in a few hours and would be keen to know what things I may not have considered 😬

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          • #20
            Well, I'd certainly divide the chamber into two, separate the woofers and add a second port.

            The old KAB battery boards are designed to work with the KAB amps, but I'm using a cheap TA2024 board so I have it wired to charge or play but not both. It seems the newer LBB battery board might work better for non-KAB amps but it wasn't available at the time. I also have two of them, which is really unnecessary for something that gets played for an hour or so at a time. One battery board is probably enough, especially if you can charge and play.

            There is no low-pass crossover, I just used a small enough cap to hopefully roll the tweeters off around the right spot. I didn't follow any recommended procedure when determining capacitor value, I just saw someone commented that it might work. So I used that value. I've seen more than a few ND65 builds that use no tweeter at all, so I'd question whether it's worth the extra $25 in parts and the pain of press-fitting an ND16FA for a sound I might not be able to hear (I work in a factory).

            For some reason, the Sure 4.0 BT boards have a hard time pairing with my phone (Google Pixel). The cheaper 2.1 BT boards do not, but they are older tech and it's still a separate component where space and volume are critical. I'd probably steer towards using an integrated amp/BT board for simplicity.

            They also sell these slick faceplates for the Bluetooth amps now with silk-screened text and pre-drilled holes. I had to make my own and it was fun but sort of a pain.

            In summary, I'd say keep it simple especially when it's going to be so small. Minimize components and simplify construction. It's tempting to cram a bunch of stuff in a form factor that is the same size as the commercial stuff, but it's just not practical.

            Hope that helps.

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            • #21
              Interesting, I was going to give the PR a go with a shared compartment and if that sounded like trash change the face plat and Chuck a divider in and add the ports.

              My other build uses the KAB boards and they are pretty good. I was looking into the sure BT board as an alternative to link up with my DTA 2 Amp.

              Always good to hear what people think about their builds, I'm on my fifth and already have rebuilt one of my first.

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