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Tzu-Jan 4 - bass bin challenge

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  • Tzu-Jan 4 - bass bin challenge

    Hello Folks,

    Some of you may be familiar with the Tzu-Jan's, my DIY Iowa 2008 mid-class winner. They are a very nice 3-way (AC130F1, MDM55, D26NC55) and now must become a 4-way to extend the bass and relieve the AC130 of those duties.

    http://techtalk.parts-express.com/pi...pictureid=1680

    Your challenge is to nominate candidates for woofer including advice on execution. There are design preferences and limitations below.

    If I end up using a nominated woofer/alignment idea, I'll be glad to send the person who came through with the big idea a pair of North D25 tweets.

    Here are the limits.

    8" preferred over 10 " (see baffle width/volume limit below).
    black cone - WAF
    cross ~ 200-300 shallow slope in the XO region, 1st order if possible
    would like to avoid metal due to breakup
    baffle width fixed at 10"
    prefer 89-90db+ to allow the woofer to provide some baffle step as needed
    60L max volume
    f3 well into the 30's highly desired

    So who is first?

  • #2
    Re: Tzu-Jan 4 - bass bin challenge

    http://www.madisound.com/catalog/pro...oducts_id=1600
    No matter where you go, there you are.
    Website

    Comment


    • #3
      Re: Tzu-Jan 4 - bass bin challenge

      I always thought I don't like metal cones, metal domes, etc. It's just because I'd heard too many cheap commercial speakers that use them but not well.

      I'm super picky. I hardly ever like speakers.

      I like the RS225, a lot.

      Use the RS225, you can even use a 1st order electrical low pass if you want, you'll just need notch filters.

      Any reason why you don't want to use a 2nd order electrical low pass on the bass bin?

      EDIT - oh - we'll need your .FRD and .ZMA files to model w/ the bass bin...

      EDIT 2: with a 2nd order electrical crossover consisting of a 3.00mH inductor in series and a 120uF cap in parallel the breakup will be ~ 50db down without a notch filter
      Attached Files
      "...this is not a subwoofer" - Jeff Bagby ;)

      Comment


      • #4
        Re: Tzu-Jan 4 - bass bin challenge

        Originally posted by maynardg View Post
        Hello Folks,

        Some of you may be familiar with the Tzu-Jan's, my DIY Iowa 2008 mid-class winner. They are a very nice 3-way (AC130F1, MDM55, D26NC55) and now must become a 4-way to extend the bass and relieve the AC130 of those duties.

        http://techtalk.parts-express.com/pi...pictureid=1680

        Your challenge is to nominate candidates for woofer including advice on execution. There are design preferences and limitations below.

        If I end up using a nominated woofer/alignment idea, I'll be glad to send the person who came through with the big idea a pair of North D25 tweets.

        Here are the limits.

        8" preferred over 10 " (see baffle width/volume limit below).
        black cone - WAF
        cross ~ 200-300 shallow slope in the XO region, 1st order if possible
        would like to avoid metal due to breakup
        baffle width fixed at 10"
        prefer 89-90db+ to allow the woofer to provide some baffle step as needed
        60L max volume
        f3 well into the 30's highly desired

        So who is first?
        You must consider Curt's Maverick with it's excellent low end.

        http://www.madisound.com/catalog/pro...oducts_id=1605

        How can you go wrong with this excellent woofer? only problem is the non-black frame.



        Of course, there are always the non-exclusive HDS models too.

        http://www.madisound.com/catalog/pro...oducts_id=1614




        As for implementation, I don't know how successful at getting a first order HP into the existing Tzu-Jan you'll be. When you add high pass elements to your woofer section, unless you swamp the resonance peak, you'll have issues getting the transfer function to stay the same as you move to the upper XO point. I played around with adding a bass bin to the Dreydel. I found that everything in the XO needed to change, because sensitivity is bumped up with the addition of the woofer.

        Either of these Peerless woofers will handle 1st order well, but I'd think you want at least second order on the XO since the new woofer will extend easily into the midrange, affecting voicing.

        Are you contemplating an active setup for the bass bin? That would involve the least tampering with the existing Tzu-Jan XO.
        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


        • #5
          Re: Tzu-Jan 4 - bass bin challenge

          The VAS on that one is prob. a little too high, but otherwise it looks nice.

          Of course, there are always the non-exclusive HDS models too.

          http://www.madisound.com/catalog/pro...oducts_id=1614
          While I would recommend the Peerless HDS woofers, the 8" black one is:

          OUT OF STOCK

          The RS225 woofers are not OOS. And they make good bass.

          EDIT: when we asked Madisound about them, they seemed to think that they were not only out of stock, but out of production.
          "...this is not a subwoofer" - Jeff Bagby ;)

          Comment


          • #6
            Re: Tzu-Jan 4 - bass bin challenge

            Pete, Critofur, your thoughts re: second order are well taken. The whole XO will need some rework. I'll have to lift existing baffle step, which is applied at the front end of the entire XO in the existing Tzu-Jan. That will alter the AC130 to MDM55 section a bit - currently at 1500.

            The new box for the top three drivers is a truncated pyramid, so that will have an effect.

            Because the current XO is cascaded, I think I'll model it in sections beginning with the MDM55/D26, save the overall results, then add the AC130, and model as a twp way, save overall results, then add the woofer and model again, trying to retain a 1st order slope. I think those shallow slopes and close spacing of drivers contribute to the good sound of the current Tzu-Jan. Don't want to lose it.

            Comment


            • #7
              Re: Tzu-Jan 4 - bass bin challenge

              Maynard,

              Have you considered another AC130 and making it a 3.5?

              I remember these from Iowa 2008 - loved 'em - they were the highlight of the event in my opinion.

              Just my two cents worth.

              Marty

              Comment


              • #8
                Re: Tzu-Jan 4 - bass bin challenge

                Maynard, I'm a big fan of the RS225, and I would be happy with one in a tapered TL. But that's so cliche. I propose a RSS265HF-4 on a front baffle slightly angled to the outside to accommodate the width requirement. With near floor placement it should have enough sensitivity. You can oversize the sealed box to account for the inductor's DCR or just to achieve a better F10 and still stay within the volume requirement. Might even have room for a TL. Besides, they are black and beautiful.

                "Looks like you may have to design your own speakers. Its not that hard." -DE Focht

                Diffraction Happens

                Comment


                • #9
                  Re: Tzu-Jan 4 - bass bin challenge

                  Originally posted by maynardg View Post
                  Hello Folks,

                  Some of you may be familiar with the Tzu-Jan's, my DIY Iowa 2008 mid-class winner. They are a very nice 3-way (AC130F1, MDM55, D26NC55) and now must become a 4-way to extend the bass and relieve the AC130 of those duties.

                  http://techtalk.parts-express.com/pi...pictureid=1680

                  Your challenge is to nominate candidates for woofer including advice on execution. There are design preferences and limitations below.

                  If I end up using a nominated woofer/alignment idea, I'll be glad to send the person who came through with the big idea a pair of North D25 tweets.

                  Here are the limits.

                  8" preferred over 10 " (see baffle width/volume limit below).
                  black cone - WAF
                  cross ~ 200-300 shallow slope in the XO region, 1st order if possible
                  would like to avoid metal due to breakup
                  baffle width fixed at 10"
                  prefer 89-90db+ to allow the woofer to provide some baffle step as needed
                  60L max volume
                  f3 well into the 30's highly desired

                  So who is first?
                  A couple more thoughts after seeing the responses so far.

                  Is a side mount option off the table? If all you're really wanting to do is augment the low end of an already well received system, why not just limit the addition to augmenting the low end?

                  Arguably the weakest performer in the chain of midrange reproduction would be the woofer if used in a 1st order approach. You also remove the least amount of low frequency information from the midwoofer.

                  The RSS265 suggestion is a very good one. You could simply build the HOSS bass bin as is and mount the Tzu right on top. It's only slightly wider than 10" at the bottom, but tapers going up for a very slim overall profile.
                  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


                  • #10
                    Re: Tzu-Jan 4 - bass bin challenge

                    A couple more thoughts after seeing the responses so far.

                    Is a side mount option off the table? If all you're really wanting to do is augment the low end of an already well received system, why not just limit the addition to augmenting the low end?

                    Arguably the weakest performer in the chain of midrange reproduction would be the woofer if used in a 1st order approach. You also remove the least amount of low frequency information from the midwoofer.

                    The RSS265 suggestion is a very good one. You could simply build the HOSS bass bin as is and mount the Tzu right on top. It's only slightly wider than 10" at the bottom, but tapers going up for a very slim overall profile.
                    I've almost had an aversion to RS drivers. Maybe not entirely accurate, but I hear a "house sound". I'd almost rather spend Scan-Speak money.

                    MG

                    Comment


                    • #11
                      Re: Tzu-Jan 4 - bass bin challenge

                      Originally posted by maynardg View Post
                      I've almost had an aversion to RS drivers. Maybe not entirely accurate, but I hear a "house sound". I'd almost rather spend Scan-Speak money.

                      MG
                      Well, in that case . . .

                      I do believe that Paul K. has just the right enclosure for this.

                      Amazing Bass, how sweet the sound.



                      I don't think you could go wrong with this one either.

                      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


                      • #12
                        Re: Tzu-Jan 4 - bass bin challenge

                        Oh the choices. I remember subjectively moving bass quality from the Scans Paul used and from the Exclusive that Curt used. I think maybe the exclusive would be a bit more forgiving, but the Scans were a bit better in the way down deep department. The Seas works in a smaller box, but won't go as deep.

                        Damn the laws of physics anyway!

                        Comment


                        • #13
                          Re: Tzu-Jan 4 - bass bin challenge

                          How about this in 60L vented?


                          http://www.madisound.com/catalog/pro...oducts_id=8530

                          Comment


                          • #14
                            Re: Tzu-Jan 4 - bass bin challenge

                            Originally posted by maynardg View Post
                            And only .6mH inductance too.

                            Too bad a more exotic cone material is off the table, because this is an excellent woofer too.

                            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


                            • #15
                              Re: Tzu-Jan 4 - bass bin challenge

                              Originally posted by maynardg View Post
                              ...I think those shallow slopes and close spacing of drivers contribute to the good sound of the current Tzu-Jan. Don't want to lose it.
                              The lower you go in freq., the farther you should be able to space the drivers without loosing anything. In fact, I would say the primary concern when placing the low freq. "bass bin" driver should be canceling floor bounce. IMHO eliminating floor bounce cancellation is far more rewarding sonically than anything gained by trying to address other concerns with lf driver placement (other than the possible exception of achieving more "boundary gain" lf reinforcement).

                              RE Pete's last pictures posted: Oh, the Kevlar/CF woofer has a nice responce, I've worked with those in the past. Just paint it black! Seriously, the mass added by a thin coat of black spray paint is not going to hurt anything :D

                              Also, again IMHO - the sonic benefit to a front facing low woofer is so substantial that I would really hesitate to move it to the side, if at all possible.

                              RE: The "RS House Sound" - hmm, well, it's only the RS225 that I've heard and liked so much, I don't have any favorable opinions about the smaller woofers. I've seen a lot of people expressing opinions in favor of cone materials such as Nomex, paper, or other non-metal cones being quite preferable for the midrange, but thumbs up to aluminum for the low woofer.

                              Before you decide - I want to dig up the info about the new Exodus Audio 6.5" XBL^2 mini-subwoofer, his new replacement for the old EX-6.5 looks very nice, and the price will be very reasonable. "Anarchy" I think it's called?

                              Youtube video: http://www.youtube.com/watch?v=-iGD0p0E42A
                              "...this is not a subwoofer" - Jeff Bagby ;)

                              Comment

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