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Flex Your PCD Mettle:

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  • Re: Flex Your PCD Mettle:

    I'm not so sure the slope at the extreme high end is an issue; it's certainly not in EconoWave Deluxe, which I've been listening to for weeks now. I was mostly just commenting on the differences in the results of these two approaches.

    See Geddes's Abbey, for example, now $1000 EACH more in kit form than Deluxe:

    http://www.gedlee.com/abbey.htm

    http://www.gedlee.com/Loudspeakers.htm

    [I'll try the impedance taming.... ]

    Comment


    • Re: Flex Your PCD Mettle:

      Originally posted by Zilch View Post
      I'm not sure the slope at the extreme high end is an issue; it's certainly not in EconoWave Deluxe, which I've been listening to for weeks now.

      See Geddes's Abbey, for example, now $1000 EACH more in kit form than Deluxe:

      http://www.gedlee.com/abbey.htm

      http://www.gedlee.com/Loudspeakers.htm
      Hey, the extra components are fairly cheap to improve it, at least on paper, so why not give it a whirl? Might be an audible improvement. ;)

      I like the look of this Deltalite response plot. And the price sure is right. I could see this thing in a tower, folded, tapered TL. It would make a nearly full range two way with some serious low end grunt that most dual 8" systems couldn't touch.
      R = h/(2*pi*m*c) and don't you forget it! || Periodic Table as redrawn by Marshall Freerks and Ignatius Schumacher || King Crimson Radio
      Byzantium Project & Build Thread || MiniByzy Build Thread || 3 x Peerless 850439 HDS 3-way || 8" 2-way - RS28A/B&C8BG51

      95% of Climate Models Agree: The Observations Must be Wrong
      "Gravitational systems are the ashes of prior electrical systems.". - Hannes Alfven, Nobel Laureate, Plasma physicist.

      Comment


      • Re: Flex Your PCD Mettle:

        I like the look of this Deltalite response plot. And the price sure is right. I could see this thing in a tower, folded, tapered TL. It would make a nearly full range two way with some serious low end grunt that most dual 8" systems couldn't touch.
        Attached Files
        Last edited by Zilch; 03-26-2010, 02:42 PM.

        Comment


        • Re: Flex Your PCD Mettle:

          Looks great Zilch!

          congratulations,

          Dan
          "guitar polygamy is a satisfying and socially acceptable alternative lifestyle."~Tony Woolley
          http://dtmblabber.blogspot.com/
          http://soundcloud.com/dantheman-10

          Comment


          • Behind the Curtain:

            Originally posted by dantheman View Post
            Looks great Zilch!
            Thanks, Dan!

            Now what? :p



            [Guess I'll listen awhile.... ;) ]
            Attached Files
            Last edited by Zilch; 03-26-2010, 02:56 PM.

            Comment


            • Re: Flex Your PCD Mettle:

              Zilch and Pete, this is some awesome work.

              Zilch, do you have any feedback on the subjective differences between the HO, LF and Deltalite? Are they distinguishable?

              Comment


              • Re: Flex Your PCD Mettle:

                Originally posted by coctostan View Post
                Zilch, do you have any feedback on the subjective differences between the HO, LF and Deltalite? Are they distinguishable?
                Recognize first that these have been whirlwind rounds of loudspeaker design with no opportunity for extended quality listening anywhere outside ZilchLab.

                The highs are the same, because they are all mated with the same compression driver/waveguide combination in the same cabinets crossed flat within a few dB in the same region.

                The mids are very similar and a step up in clarity and dynamics, in general, from the lower-efficiency drivers with which I am more familiar in the EconoWave format. I'd certainly have to do more rigorous A/B listening to distinguish among these three in this respect, and against others to ascertain whether there is, in fact, an Eminence sound character, and what that might be.

                On the low end, there are easily discernable differences, with the caveat that I am using all of them in this same small (1.6 cuft) vented alignment tuned to 30 Hz, and paying no attention whatsoever to how each might be optimized. All are being played under the same conditions, on the wide test stand you see in the pics, at least 1m away from all boundaries, 2m to the side and rear, typical.

                Given these conditions, I am hearing what Dennis's models suggest, basically:

                LF will play extended bass with EQ assist, and would probably not need that with boundary reinforcement as a full-range system without sub(s). HO and DL try but can't pull it off, and need subs or a more optimum low frequency alignment as others have suggested above. Recognizing that most home theater installations incorporate subs, either of the latter two would be well adapted to this use.

                Also significant in the results thus far is that in this small vented alignment, neither HO nor DL have a major efficiency advantage over LF; their 100 dB sensitivity is measured midband, and we give much of that up in the course of normalizing their respective performances to the region of 100 Hz.

                Though I haven't tried it myself yet, I expect Dennis is also correct in suggesting that LF would do as well closed-box in this respect as the others could do vented in this small box size. Does this mean that LF is the slam-dunk driver of preference? Nope, merely that there is plenty of fun yet to be found in discovering how well these three woofers might perform in alternative alignments.... :D
                Last edited by Zilch; 03-26-2010, 03:32 PM.

                Comment


                • Re: Flex Your PCD Mettle:

                  Thanks for the reply. That is exactly what I was looking for.

                  My intent is to build these soffit style in the corners of my theater so they will cross Geddes style. This should give them a nice pi cornerhorn effect too and I will be able to build the enclosures much larger. I have never built an in-wall style speaker, so we will see how the bass response works out. My plan is to try your Econo passive layout, a tweaked Parham style passive and an active through a Crown XTI1000. We'll see how they work out.

                  Your crossover work has definitely been helpful and your contributions to the DIY community with the Econowave should be commended.

                  Comment


                  • Re: Flex Your PCD Mettle:

                    Originally posted by coctostan View Post
                    Your crossover work has definitely been helpful and your contributions to the DIY community with the Econowave should be commended.
                    Thank you for this.

                    I believe it is safe to say that we have successfully brought a different design perspective to literally hundreds of DIYers over the past two years, and the results have been most gratifying....

                    Comment


                    • Re: Flex Your PCD Mettle:

                      Originally posted by coctostan View Post
                      Thanks for the reply. That is exactly what I was looking for.

                      My intent is to build these soffit style in the corners of my theater so they will cross Geddes style. This should give them a nice pi cornerhorn effect too and I will be able to build the enclosures much larger. I have never built an in-wall style speaker, so we will see how the bass response works out. My plan is to try your Econo passive layout, a tweaked Parham style passive and an active through a Crown XTI1000. We'll see how they work out.

                      Your crossover work has definitely been helpful and your contributions to the DIY community with the Econowave should be commended.
                      If you build these in-wall, the crossover will not be optimized for that use, and will suffer from excessive midbass due to the crossover employing baffle step compensation, which won't be needed with your in-wall effort.
                      R = h/(2*pi*m*c) and don't you forget it! || Periodic Table as redrawn by Marshall Freerks and Ignatius Schumacher || King Crimson Radio
                      Byzantium Project & Build Thread || MiniByzy Build Thread || 3 x Peerless 850439 HDS 3-way || 8" 2-way - RS28A/B&C8BG51

                      95% of Climate Models Agree: The Observations Must be Wrong
                      "Gravitational systems are the ashes of prior electrical systems.". - Hannes Alfven, Nobel Laureate, Plasma physicist.

                      Comment


                      • Re: Flex Your PCD Mettle:

                        Most importantly, we have illustrated how this might be accomplished for any alignmnent using inexpensive tools.

                        [I truly hope this aspect is not escaping readers here.... ]

                        Comment


                        • Re: Behind the Curtain:

                          Originally posted by Zilch View Post
                          Thanks, Dan!

                          Now what? :p
                          Get a beer, some music, and enjoy.

                          Dan
                          "guitar polygamy is a satisfying and socially acceptable alternative lifestyle."~Tony Woolley
                          http://dtmblabber.blogspot.com/
                          http://soundcloud.com/dantheman-10

                          Comment


                          • Re: Flex Your PCD Mettle:

                            If you build these in-wall, the crossover will not be optimized for that use, and will suffer from excessive midbass due to the crossover employing baffle step compensation, which won't be needed with your in-wall effort.
                            Definitely. I plan to tweak your crossover to fit my requirements. I think it should get me in the ballpark though. I've done some crossovers and have the necessary tools, but sometimes it helps to have a nice topology to start with.

                            Comment


                            • Re: Flex Your PCD Mettle:

                              Originally posted by coctostan View Post
                              Definitely. I plan to tweak your crossover to fit my requirements. I think it should get me in the ballpark though. I've done some crossovers and have the necessary tools, but sometimes it helps to have a nice topology to start with.
                              Tweeter level will need to come up at least 4dB. That means dramatic changes to values to keep the same transfer function, only raised. Flattening the woofer transfer function is another matter. Changes there are even more substantial.

                              I'm going to suggest a starting point for you. I used Zilch's plots, but ignored everything below the baffle step.

                              Here's the PCD sim, and it looks really nice, to me anyway. In the top plot, you see driver responses, power response (waveguide not included), and the tweeter reverse null. It seems the forward axis is straight ahead on this one, and there's nothing wrong with that I would assume.

                              R = h/(2*pi*m*c) and don't you forget it! || Periodic Table as redrawn by Marshall Freerks and Ignatius Schumacher || King Crimson Radio
                              Byzantium Project & Build Thread || MiniByzy Build Thread || 3 x Peerless 850439 HDS 3-way || 8" 2-way - RS28A/B&C8BG51

                              95% of Climate Models Agree: The Observations Must be Wrong
                              "Gravitational systems are the ashes of prior electrical systems.". - Hannes Alfven, Nobel Laureate, Plasma physicist.

                              Comment


                              • Re: Flex Your PCD Mettle:

                                Originally posted by Skywave-Rider View Post
                                Maybe I missed it, but have you compared distortion measurements between the Kappalite and Deltalite?

                                Attached Files

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