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  • Re: Flex Your PCD Mettle:

    I will make some pictures of baffle and upload them in few minutes...

    EDIT: Here it is



    http://img222.imageshack.us/img222/4543/img0103qy.jpg

    Comment


    • Re: Flex Your PCD Mettle:

      OK, I ran a sim with no acoustic offset, with the mic position midway between woofer and tweeter, and a baseline sensitivity of 92dB.

      Woofer XO:
      2mH, 15uF

      Tweeter XO: (pos polarity)
      4.7uF, .2mH (.2Ohm 20ga)

      L-pad:
      3.3 series, 6.8 shunt.

      Waveguide EQ:
      series connected .05mH, 10uF, 2 Ohm. Placed in parallel with the 6.8 Ohm resistor and tweeter terminals.
      That is 2KHz xover frequency... I thought that whole point of Econowave is to, in some way, replicate the JBL 4425 but with constant directivity.

      Every one of the JBL top line speakers had xover frequency between 700 and 1500 Hz. I think that 2000Hz is way high for 12" midbass and for what Zilch was trying to do...

      I do not have measuring equipment yet so i will have to wait to finish the speakers and then invite someone to do the measuring and tweaking of the crossover. I will post my results here...

      Regards...

      Comment


      • Re: Flex Your PCD Mettle:

        Originally posted by Zvuchniak View Post
        That is 2KHz xover frequency... I thought that whole point of Econowave is to, in some way, replicate the JBL 4425 but with constant directivity.

        Every one of the JBL top line speakers had xover frequency between 700 and 1500 Hz. I think that 2000Hz is way high for 12" midbass and for what Zilch was trying to do...

        I do not have measuring equipment yet so i will have to wait to finish the speakers and then invite someone to do the measuring and tweaking of the crossover. I will post my results here...

        Regards...
        OK, even more EQ.
        I like the way this looks!!! :D

        1500Hz LR4

        Woofer:

        2.2mH, 22uF

        Tweeter: pos polarity

        10uF in series with 4 Ohm, .2mH shunt.

        parallel RLC BEFORE the crossover:
        .55mH, 12uF, 8 Ohm

        parallel RLC AFTER the crossover:
        .4mH, 1.5uF, 25 Ohm





        Attached Files
        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 will rather go with few dB less than 2 notch filters :D Like Z-man used to say, everyone has their own way of dealing with issues.

          Thanks for suggestions. I'll try the 12dB/o and 18 dB/o for midbass and i'll post some listening impressions after.

          If anyone has anything to say, feel free to comment. That's why the pictures i posted are here for

          Regards, Z ...
          Last edited by Zvuchniak; 02-21-2011, 10:47 AM.

          Comment


          • Re: Flex Your PCD Mettle:

            Originally posted by Zvuchniak View Post
            I will rather go with few dB less than 2 notch filters :D Like Z-man used to say, everyone has their own way of dealing with issues.

            Thanks for suggestions. I'll try the 12dB/o and 18 dB/o for midbass and i'll post some listening impressions after.

            If anyone has anything to say, feel free to comment. That's why the pictures i posted are here for

            Regards, Z ...
            Those notch filters are cheap. And they do the job of forcing the correct response from the tweeter to get LR4 acoustic.

            With only two components, the woofer is following an almost ideal LR4 slope. The tweeter/waveguide combo has some serious issues with getting that shape down to a lower frequency with a simple XO. That's why I posted the first one crossing at 2KHz.

            You also mentioned problems at 2KHz. You cannot fix it in the woofer, because the problem lies in the tweeter. Without some serious EQ, there's real linearity problems with that waveguide. When you compare it to the QSC 152i waveguide, the differences are quite apparent. Without the EQ at 2KHz on the tweeter, you'll either have the peak at 2K, or the broad dip just before it. There's also the problem with the broad bump centered around 8KHz, and EQ is the only solution for that as well.

            Personally, that WG would seem to better match a smaller format woofer instead of having to be forced to go lower in frequency to match a 12".

            Is 11 components really all that much for a 2-way that keeps response to +-2dB?
            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:

              Played with it some more. 12 components. Now, the response stays within +- 1.5dB. And look at the reverse null. 1393Hz ;)





              Attached Files
              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:

                That's sweet Pete! Thank you for your contributions. Top notch work again.

                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:

                  Those notch filters are cheap. And they do the job of forcing the correct response from the tweeter to get LR4 acoustic.

                  With only two components, the woofer is following an almost ideal LR4 slope. The tweeter/waveguide combo has some serious issues with getting that shape down to a lower frequency with a simple XO. That's why I posted the first one crossing at 2KHz.

                  You also mentioned problems at 2KHz. You cannot fix it in the woofer, because the problem lies in the tweeter. Without some serious EQ, there's real linearity problems with that waveguide. When you compare it to the QSC 152i waveguide, the differences are quite apparent. Without the EQ at 2KHz on the tweeter, you'll either have the peak at 2K, or the broad dip just before it. There's also the problem with the broad bump centered around 8KHz, and EQ is the only solution for that as well.

                  Personally, that WG would seem to better match a smaller format woofer instead of having to be forced to go lower in frequency to match a 12".

                  Is 11 components really all that much for a 2-way that keeps response to +-2dB?
                  First i want to thank you for your patience. I'm still learning on how to use PCD and how to make xovers.

                  It is not the price of components that i was worried about (they are fairly cheap). I've seen quite a bit of speakers that had few kilos of xovers but sounded bad.

                  Few bad experiences led me to believe that any speaker that has too much components on the xover will sound bad.

                  I trust you on this one and i agree with you in almost everything you've wrote in this post. I am aware of QSC supremacy over this WG but i could not find it anywhere in Serbia. I was looking for JBL PT-F95 or QSC-HPR152i but zilch

                  There are no other WG's here except this type so i used what i had.

                  Thanks again Pete. I will use xover you suggested to me and then post some pictures and listening impressions. If nothing else, i hope that i influenced some of the guys, that are lurking, to activate little with their own ideas :D

                  Regards, Zvuchniak ...

                  Comment


                  • Re: Flex Your PCD Mettle:

                    Originally posted by Zvuchniak View Post
                    First i want to thank you for your patience. I'm still learning on how to use PCD and how to make xovers.

                    It is not the price of components that i was worried about (they are fairly cheap). I've seen quite a bit of speakers that had few kilos of xovers but sounded bad.

                    Few bad experiences led me to believe that any speaker that has too much components on the xover will sound bad.

                    I trust you on this one and i agree with you in almost everything you've wrote in this post. I am aware of QSC supremacy over this WG but i could not find it anywhere in Serbia. I was looking for JBL PT-F95 or QSC-HPR152i but zilch

                    There are no other WG's here except this type so i used what i had.

                    Thanks again Pete. I will use xover you suggested to me and then post some pictures and listening impressions. If nothing else, i hope that i influenced some of the guys, that are lurking, to activate little with their own ideas :D

                    Regards, Zvuchniak ...
                    Well, you could go with a much simplified XO, and then smooth the result with active EQ.
                    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


                    • Porting of the knock down cab

                      Can someone tell me what the porting is for these cabs - I am going to build a 'to Zilch' build of the 'high power pro' e-waves that will sit on a pair of B380 clones. I have spent many hours searching but can't seem to find the porting info on these.
                      Thanks
                      Steve
                      The woofers should arrive Thursday.

                      Comment


                      • Re: Flex Your PCD Mettle:

                        To the best of my knowledge, the trap cabs Zilch used for testing were not tuned or optimized for any particular woofer (except for maybe the first one in the box). I would keep the same baffle (dimensions, c-c distance, horizontal offsets) but look at optimizing volume and tuning for your application.

                        Comment


                        • Re: Porting of the knock down cab

                          Originally posted by srbliss View Post
                          Can someone tell me what the porting is for these cabs - I am going to build a 'to Zilch' build of the 'high power pro' e-waves that will sit on a pair of B380 clones. I have spent many hours searching but can't seem to find the porting info on these.
                          Thanks
                          Steve
                          The woofers should arrive Thursday.
                          I use WinISD to model enclosures below 200 Hz.

                          http://www.linearteam.dk/default.aspx?pageid=winisdpro

                          http://www.avsforum.com/avs-vb/showthread.php?t=883104

                          It has really good help files. Make sure to follow the specific order they recommend for inputting the driver parameters, it matters.


                          Cheers, Joe

                          Comment


                          • Re: Flex Your PCD Mettle:

                            Originally posted by Zvuchniak View Post
                            First i want to thank you for your patience. I'm still learning on how to use PCD and how to make xovers.

                            It is not the price of components that i was worried about (they are fairly cheap). I've seen quite a bit of speakers that had few kilos of xovers but sounded bad.

                            Few bad experiences led me to believe that any speaker that has too much components on the xover will sound bad.

                            I trust you on this one and i agree with you in almost everything you've wrote in this post. I am aware of QSC supremacy over this WG but i could not find it anywhere in Serbia. I was looking for JBL PT-F95 or QSC-HPR152i but zilch

                            There are no other WG's here except this type so i used what i had.

                            Thanks again Pete. I will use xover you suggested to me and then post some pictures and listening impressions. If nothing else, i hope that i influenced some of the guys, that are lurking, to activate little with their own ideas :D

                            Regards, Zvuchniak ...

                            Waveguides from Poland:
                            http://www.diysoundgroup.com/WaveGuides.htm

                            They are doing a group buy at DIY audio.

                            I used to be like you too, about crossovers. To me simpler the better.

                            Now my xover has 17 parts (I think). My best sounding speaker ever.

                            With 3 notch filters.

                            Done right it's great sounding.

                            Done wrong it's sounds like crap.

                            Comment


                            • Re: Flex Your PCD Mettle:

                              Originally posted by bruson View Post
                              Waveguides from Poland:
                              http://www.diysoundgroup.com/WaveGuides.htm

                              They are doing a group buy at DIY audio.

                              I used to be like you too, about crossovers. To me simpler the better.

                              Now my xover has 17 parts (I think). My best sounding speaker ever.

                              With 3 notch filters.

                              Done right it's great sounding.

                              Done wrong it's sounds like crap.
                              Thanks for the tip ;)

                              Comment


                              • Re: EconoWave Deluxe:

                                In my Xover I've gone back to a Gedlee style.
                                I looked at a few photos of Nathan and Abbey xovers on various sites of various ages, 2008-2010.
                                I measured all the inductors and caps physical sizes using Madisound and stuff I have on hand and came up with a educated guess for values. Photoshop was a big help. So were Gedlee posts in DIY and his diy builders. I'm sure they are not exactly what he uses now, especially as he has improved them in late 2010.
                                Listening tests tell me my versions of Gedlee xovers improve it more than my version of a Zilch filter.
                                On a simple FR they no real difference from Zilch-type xover. None. Just like using teflon caps and Mills resistors showed no FR difference.
                                But everything sounded cleaner and clearer. My girlfriend and my son even noticed. But the FR didn't. It's not worth posting the charts.
                                Now I know why guys who live and die by measurements laugh at my audio hallucinations, er, subjective listening decisions. I couldn't measure any difference, but it sounded so much better. Gedlee is on to something that hasn't been discussed on this thread.

                                I had some air core inductors from Madisound. The white plastic type everyone uses.
                                After I thought my xover sounded great from guessing Gedlee parameters I bought some Jensen Air cores from PE.


                                Cleaner and clearer sound. The spacing and layout of inductors didn't change that much.
                                Next I strung them up over the MDF for fun and to use up crap I had laying around.
                                You guessed it, cleaner and clearer sound.

                                Mutual inductance aint the answer, unless inductors in a notch filter being 3-5 inches from each other makes a difference.

                                I'm not gonna bother to measure it.
                                Why would magnetics, inductors, be so affected by being lifted off MDF? Dielectric constant?
                                I think there is an E-field around inductors besides a magnetic field, or does MDF affect magnetics too?

                                Why can't I measure these differences?

                                Comment

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