InDIYana build - SuperNova Minimus

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  • Jake
    Midrange Member
    • Nov 2017
    • 396

    #61
    Coming along realike nice wogg. The duratex will look nice with the walnut all shined up.

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    • wogg
      Seasoned Veteran
      • Nov 2015
      • 1967

      #62
      Finished and back together, leads still out the front for crossover prototyping.
      Electronics engineer, woofer enthusiast, and musician.
      Wogg Music
      Published projects: PPA100 Bass Guitar Amp, ISO El-Cheapo Sub, Indy 8 2.1 powered sub, MicroSat, SuperNova Minimus

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      • Billet
        Midrange Member
        • Sep 2017
        • 490

        #63
        Looks nice!

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        • wogg
          Seasoned Veteran
          • Nov 2015
          • 1967

          #64
          Originally posted by Billet
          Looks nice!
          Thanks! I feel like I'm cheating a bit compared to the other builds, so I'm counting on nostalgia factor.
          Electronics engineer, woofer enthusiast, and musician.
          Wogg Music
          Published projects: PPA100 Bass Guitar Amp, ISO El-Cheapo Sub, Indy 8 2.1 powered sub, MicroSat, SuperNova Minimus

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          • Billet
            Midrange Member
            • Sep 2017
            • 490

            #65
            My boxes are made this year but in the same general nostalgic theme. Maybe we could try to park them on the same table at InDIYana?

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            • KEtheredge87
              Seasoned Veteran
              • Jan 2015
              • 1049

              #66
              Originally posted by wogg
              Thanks! I feel like I'm cheating a bit compared to the other builds, so I'm counting on nostalgia factor.
              Nothing wrong with nostalgia factor! I played that card HARD last year with my SuperBees ;) I've never heard the original Nova 15's, but I am very excited to hear your upgraded rendition. InDIYana is going to be great this year!
              Voxel Down Firing with Dayton SA70
              Translam Subwoofers - The Jedi Mind Tricks
              The Super Bees - Garage 2 way
              SevenSixTwo - InDIYana 2018 Coax
              The Defiants - InDIYana 2019 "Bare Minimum" Build

              Comment

              • Kevin K.
                Seasoned Veteran
                • Sep 2014
                • 1872

                #67
                I like the old school look, nice work!
                My "No-Name" CC Speaker
                Kerry's "Silverbacks"
                Ben's Synchaeta's for Mom
                The Archers
                Rick's "db" Desktop CBT Arrays
                The Gandalf's

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                • wogg
                  Seasoned Veteran
                  • Nov 2015
                  • 1967

                  #68
                  Thanks KEtheredge87 and Kevin K. ! Really looking forward to this one, I've only ever been to MWAF so this should be a cool contrasting experience.
                  Electronics engineer, woofer enthusiast, and musician.
                  Wogg Music
                  Published projects: PPA100 Bass Guitar Amp, ISO El-Cheapo Sub, Indy 8 2.1 powered sub, MicroSat, SuperNova Minimus

                  Comment

                  • wogg
                    Seasoned Veteran
                    • Nov 2015
                    • 1967

                    #69
                    Used some clippy test leads to prototype the crossover together as simulated, and looky there, they are pretty much the same. The overlay is the actual ARTA measurement.

                    Click image for larger version

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                    Here's the system distortion measurement, under 1% everywhere.
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                    And the measured reverse null. This doesn't seem that deep, but it's there.
                    Click image for larger version

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                    This is only 1 speaker so far, now I need to assemble its mate and hope it's the same. I did blast some music through the 1 out in the middle of the room like it was. I pretty much hate mono music though, especially when it's not actually mono but just the L channel of a stereo track. That made it hard to have actual impressions, and I did find the bass weak. I do tend to like bass boosted systems though, so I'm reserving my opinion on that part until they're both together. The port isn't glued at the moment, so I can adjust tuning. May need to go higher to punch up 50Hz, but that will require sawing off some of the elbow. After some proper listening...
                    Electronics engineer, woofer enthusiast, and musician.
                    Wogg Music
                    Published projects: PPA100 Bass Guitar Amp, ISO El-Cheapo Sub, Indy 8 2.1 powered sub, MicroSat, SuperNova Minimus

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                    • jhollander
                      Seasoned Veteran
                      • Oct 2006
                      • 5261

                      #70
                      A 1.2 mH inductor on the woofer looks light. Might want to take a near field and blend in
                      John H

                      Synergy Horn, SLS-85, BMR-3L, Mini-TL, BR-2, Titan OB, B452, Udique, Vultus, Latus1, Seriatim, Aperivox,Pencil Tower

                      Comment

                      • wogg
                        Seasoned Veteran
                        • Nov 2015
                        • 1967

                        #71
                        Originally posted by jhollander
                        A 1.2 mH inductor on the woofer looks light. Might want to take a near field and blend in
                        Yeah, I'm going to have to figure that out. That will tell me if it's flat and I just like bass or if I under did the baffle step due to my measurements ending at 300Hz. The downside of using the iMM6 like I am is that I can't use a mic stand, so I have to basically hold the computer in place by hand to take a close mic sweep. Not exactly ideal, but should get me in the ball park.

                        Also...

                        What's a good tool to blend both the close mic woofer measurement and a port measurement? I played with Blender in Excel to do that, but wasn't sure about the port part. The woofer blend is intuitive, but the port is not. I think I have to adjust the SPL manually using the radiating diameter formula, then add it on the tab that is typically the baffle signature.
                        Electronics engineer, woofer enthusiast, and musician.
                        Wogg Music
                        Published projects: PPA100 Bass Guitar Amp, ISO El-Cheapo Sub, Indy 8 2.1 powered sub, MicroSat, SuperNova Minimus

                        Comment

                        • KEtheredge87
                          Seasoned Veteran
                          • Jan 2015
                          • 1049

                          #72
                          Originally posted by wogg

                          What's a good tool to blend both the close mic woofer measurement and a port measurement? I played with Blender in Excel to do that, but wasn't sure about the port part. The woofer blend is intuitive, but the port is not. I think I have to adjust the SPL manually using the radiating diameter formula, then add it on the tab that is typically the baffle signature.
                          Hey Wogg, it sounds like you're on the right track with the blender tool. I know Jeff Bagby's white-paper mentions summations of port response with the nearfield response, but I do not recall an actual example. Within my own brain, I wonder how things would be different if you have front firing ports vs. rear firing ports? If Jeff B. ever gets a wild hair to instruct the masses further... perhaps an example of this would help!
                          Voxel Down Firing with Dayton SA70
                          Translam Subwoofers - The Jedi Mind Tricks
                          The Super Bees - Garage 2 way
                          SevenSixTwo - InDIYana 2018 Coax
                          The Defiants - InDIYana 2019 "Bare Minimum" Build

                          Comment

                          • jhollander
                            Seasoned Veteran
                            • Oct 2006
                            • 5261

                            #73
                            The baffle response tends to flatten out before roll off so without the port the blended response will give you an idea of the reduction required for the baffle step. Without blending you could target -6 dB from the peak woofer response near 1K and be close.
                            John H

                            Synergy Horn, SLS-85, BMR-3L, Mini-TL, BR-2, Titan OB, B452, Udique, Vultus, Latus1, Seriatim, Aperivox,Pencil Tower

                            Comment

                            • wogg
                              Seasoned Veteran
                              • Nov 2015
                              • 1967

                              #74
                              This is how you start gathering a bin of extra crossover parts...

                              So I did the close mic measurement and port combination. Reading through Jeff's white paper again, he uses PCD to sum the woofer and port, then Blender to add that to the far field. I use WinPCD, but the process is similar. I just added the port and cone close mic sweeps as a woofer and tweeter and added them without any crossover to mess with them, using the woofer ZMA for both.

                              Click image for larger version

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                              Then the sum was saved out, and pulled into blender to mate with the far field. That was processed for min phase, as was the tweeter far field and the system sum far field. Then it was back into WinPCD for checking the crossover. With all files processed for min phase, and the far field woofer + tweeter not including the close mic part, I found the Z offset alignment not as clean as it was before. I did my best to get it close and went from there.

                              Long story short, I was about 3 dB short of full baffle step. That would be great for near wall or bookshelf placement, but not for stands in the middle of a room. So... I tweaked the crossover and bought more parts.

                              Here's the new crossover with an overlay representing the prior version without the close mic, you can see the 3 extra dB of baffle step applied.
                              Click image for larger version

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                              Electronics engineer, woofer enthusiast, and musician.
                              Wogg Music
                              Published projects: PPA100 Bass Guitar Amp, ISO El-Cheapo Sub, Indy 8 2.1 powered sub, MicroSat, SuperNova Minimus

                              Comment

                              • wogg
                                Seasoned Veteran
                                • Nov 2015
                                • 1967

                                #75
                                For some improved listening testing, I pulled one of my studio monitors off the stand and plopped the L speaker in it's place. Without the baffle step my Dynaudio definitely had a bit stronger bass, but the rest of the spectrum was very comparable between them. I didn't sense any odd imaging due to any major response variations between L and R. It was really pleasant to listen to, and I burned some time just playing music while tweaking the crossover.

                                Very nice... coming together!
                                Electronics engineer, woofer enthusiast, and musician.
                                Wogg Music
                                Published projects: PPA100 Bass Guitar Amp, ISO El-Cheapo Sub, Indy 8 2.1 powered sub, MicroSat, SuperNova Minimus

                                Comment

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