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  • My References

    I first built these about eight to ten years ago. They started out as a 2.5 way with the same Vifa PL18W0O9 woofers, a Vifa D27TG45 tweeter, and a Madisound designed crossover. They were decent but never really grabbed me. Over the years, I swapped in a Seas H1212 tweeter (I am one of the few who has always preferred metal domes..). As I started learning PCD and tinkering with crossover designs I did a few revisions but was never any happier than I was in the beginning.

    I started a thread looking for suggestions on my last revision and a couple people suggested going to a two-way. I modeled it and was able to cut the parts count down and come up with what looked like a good model. I have other projects in the works which could use the parts, so it was a win-win. The two-way sounded much better in my opinion than any of the previous 2.5 way versions. While they are probably considered 4 ohm nominal impedance with the parallel woofers, my 6 ohm minimum Pioneer VSX49txi receiver runs them with no problems.

    The cabinets are made of 1" MDF and the woofers share about 1ft3 vented. There are two stick braces for the side walls. The feet are oak with spikes. The crossover is bi-ampable and the rear bears a terminal cup with two sets of binding posts. The finish is PE cherry vinyl film (NLA). It looks good in a dim room from 2m away, but light exposes my poor application and plenty of bubbles. I have more if it ever bothers me enough to redo.

    They never had a name before, but I am calling them the References. While an unoriginal name, it is exactly what they are to me, as anything else I build, better or worse, has and will be compared against them.

    Sorry I don't have build photos, but they were built long before I knew there was a speaker forum. Thanks for looking! :D

    EDIT: I revised the crossover.
    Attached Files
    Last edited by dynamo; 10-12-2016, 01:23 PM. Reason: Removed the 2r tweeter resistor after the crossover and reflected that in the schematic
    Projects:

    transcenD: http://techtalk.parts-express.com/fo...5035-transcend
    Summits: http://techtalk.parts-express.com/sh...75-The-Summits
    References: http://techtalk.parts-express.com/sh...-My-References
    Vintage Style 2-way: http://techtalk.parts-express.com/sh...-vintage-2-way

  • #2
    Re: My References

    Nice driver choice.

    I think 2.5-ways are hard to get right. You HAVE to look away from the graphs for it to sound right. Our training tells us it should just fill in +6 dB in the bass. But that ends up being too much, and sounded bloated (or "closed-in" as you say). So you gotta play with the balance of everything for it to start working out. It's hard. If the 2-way works for you, and sounds better, keep it!
    Isn't it about time we started answering rhetorical questions?

    Paul Carmody's DIY Audio Projects
    Twitter: @undefinition1

    Comment


    • #3
      Re: My References

      Thanks Paul, I am (now) very happy with the drivers! Too bad the woofers are NLA, but I believe they have a clone under the Scan name at least.
      Projects:

      transcenD: http://techtalk.parts-express.com/fo...5035-transcend
      Summits: http://techtalk.parts-express.com/sh...75-The-Summits
      References: http://techtalk.parts-express.com/sh...-My-References
      Vintage Style 2-way: http://techtalk.parts-express.com/sh...-vintage-2-way

      Comment


      • #4
        Re: My References

        Your "tank" (notch) 1.5mH || 0.2uF LOOKs to be targeting 9kHz, but I wouldn't know why?
        Where did you get your F/Z files for modeling purposes, if I might ask?

        Comment


        • #5
          Re: My References

          I'd have to go back and play with the model to remember why I came to use that tank filter, I don't recall off the top of my head. The models are manufacturer charts run thru response modeler. I did a quick overall measurement with my imm6 and it looks decent, slight dip around the crossover point.
          Projects:

          transcenD: http://techtalk.parts-express.com/fo...5035-transcend
          Summits: http://techtalk.parts-express.com/sh...75-The-Summits
          References: http://techtalk.parts-express.com/sh...-My-References
          Vintage Style 2-way: http://techtalk.parts-express.com/sh...-vintage-2-way

          Comment


          • #6
            Re: My References

            You probably know this , but if you modeled the tank cap, THEN changed the inductor (making it smaller), the target freq. for the notch would go up.

            Comment


            • #7
              Re: My References

              Originally posted by Chris Roemer View Post
              You probably know this , but if you modeled the tank cap, THEN changed the inductor (making it smaller), the target freq. for the notch would go up.
              I just got a chance to look at it in PCD and all I can figure is that in all the playing around I did with different order filters, different inductors, different approaches, etc. is that it got put in at some experimental stage, and then was still there when I arrived at the design I settled on and everything looked good, so I never went back and tried taking it out. It doesn't seem to be hurting anything, it's just that it isn't really doing anything either. If I ever need the caps for something else, I know right where to find them to snip them out :D

              Thanks for noticing it.
              Projects:

              transcenD: http://techtalk.parts-express.com/fo...5035-transcend
              Summits: http://techtalk.parts-express.com/sh...75-The-Summits
              References: http://techtalk.parts-express.com/sh...-My-References
              Vintage Style 2-way: http://techtalk.parts-express.com/sh...-vintage-2-way

              Comment


              • #8
                Re: My References

                Schematic revision after Chris' keen observation of what is ultimately an unnecessary part left in for the final design. Thanks Chris.

                EDIT: new schem added for crossover revision as shown in post 1
                Attached Files
                Last edited by dynamo; 01-20-2016, 02:45 PM. Reason: new crossover
                Projects:

                transcenD: http://techtalk.parts-express.com/fo...5035-transcend
                Summits: http://techtalk.parts-express.com/sh...75-The-Summits
                References: http://techtalk.parts-express.com/sh...-My-References
                Vintage Style 2-way: http://techtalk.parts-express.com/sh...-vintage-2-way

                Comment


                • #9
                  So I decided I wanted the Seas tweeters for a different project, so I pulled them. I wasn't completely happy with the project I had the original D27TG45-06 Vifa tweeters moved to, so I scrapped them and moved the D27s back to these and updated the crossover to suit. The D27s sound pretty nice back with the PL18s (I think this was a pretty common combo back when these drivers were available. I didn't have time to measure, but have included the sim and schematic below in the event anybody has any of these laying around and is interested.
                  Projects:

                  transcenD: http://techtalk.parts-express.com/fo...5035-transcend
                  Summits: http://techtalk.parts-express.com/sh...75-The-Summits
                  References: http://techtalk.parts-express.com/sh...-My-References
                  Vintage Style 2-way: http://techtalk.parts-express.com/sh...-vintage-2-way

                  Comment

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