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  • Re: Flex Your PCD Mettle:

    You're right, I looked up 8", not the correct piston diameter.

    Standing by.
    http://www.nytimes.com/2010/10/14/bu...html?src=busln

    http://mixonline.com/mag/audio_new_york_metro_46/

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    • Re: Flex Your PCD Mettle:

      Hey Zilch,

      My Delite x-overs are assembled. The drivers are playing sans cabinet on the floor. I'm getting a head start on the break-in. I plan to take these to The Mid-West Audio Fest

      Does the DE250 break in? How sensitive is the driver response to diaphragm positioning? I'm aka "truth seeker" on your home court.
      Mongo only pawn in game of life
      ____
      Ed

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      • Re: Flex Your PCD Mettle:

        Originally posted by Zilch View Post
        It's a 10" that'll behave to ~3 kHz that's needed to mate with the QSC 122i, looks like to me....
        And would it be safe to say the 3012HO from Eminence might be a better candidate for the 122i........a bit late to the game but i really like the sound of this WG/CD combo. If a woofer upgrade is needed i'm all for it. You're pobobly going to point me away from the round WG anyways buy hey..it's worth a shot! There is a method to my madness with the 3012. Notice the wide open basket. Can you say Dipole?

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        • Re: Flex Your PCD Mettle:

          Originally posted by Mayhem13 View Post
          And would it be safe to say the 3012HO from Eminence might be a better candidate for the 122i........a bit late to the game but i really like the sound of this WG/CD combo. If a woofer upgrade is needed i'm all for it. You're pobobly going to point me away from the round WG anyways buy hey..it's worth a shot! There is a method to my madness with the 3012. Notice the wide open basket. Can you say Dipole?
          The Lambda TD10 Series is the optimal candidate for the 122i WG. It has the total displacement capacity of most pro 12" woofers, and if it has the well behaved response of its big brothers, then it should make the ideal candidate. The Lambda motors have some of the lowest THD and IM out there.

          I will be doing a WG with woofer project, and the TD10H with the RS28F in a 122i profile might make a great near full range MT (40Hz on up). Or perhaps as a large format OB mid, (Orion on steroids) with the waveguide tweeter. After hearing DoubleTap's 8" OB with waveguide loaded ScanSpeak AirCirc, I want to do something similar.
          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.

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          • Re: Flex Your PCD Mettle:

            Originally posted by edlafontaine View Post
            Does the DE250 break in? How sensitive is the driver response to diaphragm positioning? I'm aka "truth seeker" on your home court.
            I am not aware of any break-in effects with DE250, or any other compression driver, for that matter.

            Diaphragm positioning in what sense? Throat adapter?

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            • Re: Flex Your PCD Mettle:

              I hope I'm not in a battle with my own with windmills. I'll be ok. ;)

              Diaphragm positioning in what sense? Throat adapter?
              No, the centering of the cd on the throat I understand. These need a little work there.

              There have been concerns that I've read about the centering of the diaphragm within the cd. "Proper" positioning will decrease HD.

              These are my first cd's...pop a cherry...:D
              Mongo only pawn in game of life
              ____
              Ed

              Comment


              • Re: Flex Your PCD Mettle:

                With bolt-on drivers, there's a small amount of adjustability. I just look down the throat and center it by eye in the course of mounting the driver.

                Thread-on, there's nothing to adjust; it is what it is. Some builders fill small discontinuities with modeling clay. I don't obsess about such unless there's a gap, or something I can easily smooth out by hand....

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                • Re: Flex Your PCD Mettle:

                  The Lambda TD10 Series is the optimal candidate for the 122i WG.
                  Unfortunately Pete, the AE drivers are a bit rich for my blood or fiscally unobtanium. I too am thinking about an OB design with the 122i WG but a CD instead to get the most out of a level match with a driver like the the 3012HO whose open back basket is screaming for an OB application IMO. I'd like to combine this with a sealed box RS315HF actively anchoring the whole thing. I have some 16"x24" x5/8 clear cellcast acrylic sheets that might just come in handy for the baffle.

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                  • Re: Flex Your PCD Mettle:

                    Originally posted by Mayhem13 View Post
                    Unfortunately Pete, the AE drivers are a bit rich for my blood or fiscally unobtanium. I too am thinking about an OB design with the 122i WG but a CD instead to get the most out of a level match with a driver like the the 3012HO whose open back basket is screaming for an OB application IMO. I'd like to combine this with a sealed box RS315HF actively anchoring the whole thing. I have some 16"x24" x5/8 clear cellcast acrylic sheets that might just come in handy for the baffle.
                    Sounds like an interesting concept. It's just that the 3012 isn't that well behaved above 1KHz. You'd be better off going with the larger QSC waveguide that allows for a lower XO point, Econo Deluxe OB.
                    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 was pondering the larger QSC rectangular guide as it would make for a shorter enclosure and closer driver C to C spacing. I'd really like to hear an Ewave with it to see if i'd like the CD/Horn combo but all of the GTG's are far from the east coast. Maybe a post to locate any Ewave owners in my area would help.

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                      • Re: Flex Your PCD Mettle:

                        It's all of $25 more to have both QSC waveguide types on hand to try....

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                        • Attached Files
                          Last edited by Zilch; 06-10-2010, 11:15 PM.

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                          • Attached Files

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                            • Fixing Directivity, Continued:

                              The normalized horizontal polar plot also shows it's much improved:




                              New PCD files below. The C/C distance is 8.8125", mic distance 44", and I find the HF offset at 151 mm. Is that plausible? Yes, this waveguide with D220Ti driver is 7.625" deep.
                              Attached Files

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                              • Re: Flex Your PCD Mettle:

                                Zilch, stupid question from filter network fool:
                                Presumably the on axis response rise at about 1500 Hz is easily dealt with in filter summation?
                                (Referring to system response plots you posted...or is all that out the window..are you starting from scratch?)
                                http://www.nytimes.com/2010/10/14/bu...html?src=busln

                                http://mixonline.com/mag/audio_new_york_metro_46/

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