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The Neutrino - A High-Output Mini-Monitor

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  • #61
    Thanks guys!

    So, I'll go with a 20 AWG for the Tweeter, a larger 15 AWG for the 1,2mh and a 18 AWG (Air Core) for the Woofer and give it a try.
    Since Dayton and Jantzen parts are not really common in Germany (and/or hard to get for a reasonable price) I will stick to Mundorf. Should not be a problem, i guess ;-)

    Any suggestions for the damping?


    • #62
      If you won't go solid on the largest coil, a #15 would be preferable to a #18. You're trying to lower the coil's "DCR" which is resistance directly inline w/the woofer, which cuts its output, amongst other things.


      • #63
        Then you have to get them in the enclosure. That is not a large enclosure at all, and the 15AWG might not allow them to fit. I'm pretty sure, but not totally confident, that Rory used 18AWG air cores for the woofers.
        The board was the length of the enclosure, and wedged between the ports in the top. You really should not use solid-core coils on this design. The proximity to the humongous underhung motor, and the limited space will effectively nullify the value of a solid-core coil.

        A side-note- If you have them, find a large magnet and an I-core or P-core. Measure the coil value, and then place it on the magnet and measure it again. You'll find the value likely to be about a tenth of what it was.

        "Wolf, you shall now be known as "King of the Zip ties." -Pete00t
        "Wolf and speakers equivalent to Picasso and 'Blue'" -dantheman
        "He is a true ambassador for this forum and speaker DIY in general." -Ed Froste
        "We're all in this together, so keep your stick on the ice!" - Red Green aka Steve Smith

        *InDIYana event website*

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        • #64
          In fact, space is a sensitive topic which I haven't had in my mind. Thanks for saving me from a mistake!
          I just made a quick drawing of how the crossover could look like considering the tight enclosure. As there is only 2.95x9.44 inches of space at the rear side wall i HAVE to go with the smaller (18/20) coils.

          I will keep you up to date.



          • #65
            Little progress...


            • #66
              Nice job on those crossovers!
              Don't worry, if your parachute fails, you have the rest of your life to fix it.

              If we all did the things we are capable of doing, we would literally ASTOUND ourselves - Thomas A. Edison

              Some people collect stamps, Imelda Marcos collected shoes. I collect speakers.:D


              • #67
                The crossover is a difficult part of the build. For my pair, I did something that I had seen done in some commercial speakers: I purchased some small-diameter machine screws that were a few inches long, and then I drilled the terminal cup (I used the biamp terminal cup) and I mounted the crossover board physically to the inside of the terminal cup using the screws as threaded rods to stand off the board from the back wall of the cabinet just enough. I had to file away the MDF around the top edges of the terminal cup opening to get the crossover and mounting solution to fit through the hole, but it eventually did, and there was enough material left that the gasket was wide enough to seal the cabinet. If you can't do this, then I recommend making the bottom or back panel removable so you can install the crossover on the back wall.

                Best of luck and I look forward to your impressions. Just take it slow and consider each step carefully before you do it, and the results should be good.
                Technology in the service of art, for the life of the music.


                • #68
                  Thanks Rory! Nice to hear from the developer itself!
                  The crossover (and even the housing) is basically finished and everything is on its place except for the front panels since I did not buy the Tweeters yet..

                  I have solved the "space problem" a little differently: The left and right speakers are designed asymmetrically - at least in the rear part. In the left speaker the crossover sits upright on the right side of the case, in the right speaker naturally on the left side. Doing it that way I got plenty of space for the crossover. The back panel is removable and is fixed on a MDF frame (6 metric screws, glued rivet nuts). Since I always build my speakers in a way which makes it possible to re-open the case some day, the additional volume of the frame has been included in the calculation from the very beginning. In the attachment you can see how the drilling holes on the back of the left speaker look like. Above is the (single) bass reflex tube, in the middle two binding posts and below is a Neutrik Speakon Connector (prepared for never know ;-)
                  As soon as I'm able to make it to my shop (aka basement) again I will take some photos. And if maybe Santa brings me a nice pair of Seas Tweeters the Neutrino's will be ready for a first listening session by end of the year :-)
                  Last edited by T-Mo; 12-13-2018, 09:49 AM.


                  • #69
                    I'll give them a try in my 300 sq ft (is that correct? 28qm2) living room powered with solid 2x396 Watts. So any lack of efficiency is nothing I really care about :-) In case they are just too small to manage the living room they will move into the bedroom where they have to be satisfied with 2x50 Watt Class-D connected to a Raspberry Pi Vana Player ... Either way I can't wait to get them finished :-)


                    • #70
                      I'm currently modelling this design in the PE 'mini' knock down enclosure, and when I enter the driver parameters into WinISD it's calculating an Fs of something like 160hz. I've double checked the data and I can't find the problem. In any case, Rory/anyone else, can you recommend a port length/diameter for a ~.22 cu ft enclosure? I understand the bass tuning was carefully selected; I've never worked with weird small drivers like this so your input would be appreciated.