How to Find Drivers for Dipole speaker project?

Collapse
This topic is closed.
X
X
 
  • Time
  • Show
Clear All
new posts
  • intelonetwo
    Member
    • Jan 2003
    • 48

    How to Find Drivers for Dipole speaker project?

    Hi All,
    I would like to know what are the paramenters of a driver that would be good to use in a dipole loudspeaker project. For instance, Xmas, QTS, Freq Response, SPL, Qms, Qes. I know a few drivers are preferred here like the very expensive HiVi, Vifa, Seas, Scan Speak and Adire Audio drivers but are their drivers that will at least get you started?

    I would like to start experimenting with less expensive drivers like those from cheaper Dayton Audio, Peerless, Vifa, Seas, etc. I would be using a dbxDriverack or the Berhinger EQ along with a multichannel amplifier.

    Any suggestions.




    MI-II-CENTS
    ______________
    The TailWind Generation I
  • sfdoddsy
    Senior Member
    • Sep 2000
    • 496

    #2
    Thomas,

    A guy on the dipole mailing list was recommending the Rockford Fosgate RFP 3215 subwoofer. He didn't detect an air noises at pretty high levels.

    Dr Linkwitz recommends a couple of cheap Vifa drivers on his sit.

    And I still think the Lambda SB12LE could be a good choice, just going on its appearance.








    PHOENIX, off-axis response, room size, open-baffle, diffraction, dipole



    Cheers

    Steve




    Steve's DIY Dipoles
    Steve's OB Journey

    Comment

    • Hank
      Super Senior Member
      • Jul 2002
      • 1345

      #3
      Here's the MCM driver Jon recommends for his current LS project:
      I'm not a "dealer" or re-seller like Danny at GR, so Hank may have access to some good prices that way- looking at off the shelf, if I had to go with 6-1/2's on a budget, I'd try the MCM carbon fiber 55-2321. I bought four to evaluate early this year. I'll take some pics and post- it's a very decent design for the money- extended pole peice, good overhang on voice coil, a flat spider with rear venting (as with ScanSpeak, Seas, and the other better brands). With a 400 - 600 Hz crossover to an RD ribbon, should work cool. Let's say, um, 8 6-1/2's is 52", so 8 of these with an RD 50, if you don't like the imposing height of an RD75.

      Maybe I'll have to build this just to know if this can really work- I've got four of them, so I'll just need four more (for mono), plus the RD. Gee, I don't think Yvonne will go for that for my birthday, though....

      Would need baffle step comp in the crossover for the 6's; also in the RD if the crossover was as low as 400 or so.


      Somewhere around here I've got the T/S parameters for these drivers; if I remember correctly, Qts is around 0.38 or 0.4, so there's some flexibility; they can be used sealed with good results (Q of 0.5 in largish box) or in a low tuned reflex. Have to check the paper catalog.








      This side view picture doesn't show as well what you can see looking at one of these close up; judging by the overhang, Xmax is about 4 mm, which is pretty solid for a six.

      Note the flat spider and rear venting of spider/voice coil area. Pretty good for a $18.50 driver...


      So, a budget array could be 8 of these per side. Round it up with shipping and it's $320 for both sides. That's only a teensey bit more than what two ScanSpeak 7's would cost.

      To wire for power tapering, I'd wire the top three in series, and the bottom three in series, and the center two in series. Then I'd connect all three series connection in parallel. Net impedance would be about 6-1/2 ohms, a pretty reasonable load for most solid state amps.

      I would build the cabinet with sepearte chambers for the top and bottom three and the center two. I'd probably elevate the bottom of the line between six and eighteen inches from the ground; this would make the net height in the range of 60 to 72" - not short, but smaller than many of the other line arrays cabinets proposed. Place the RD 50" either centered or toward the top- esthetics would indicate centered, acoustics (for standing reproduction) suggest toward the top.

      Off the top of my head, I think the narrowest you could make this cabinet would be 16" to 18". The depth would be in range of 24" to 28", in order to absorb rear wave of planar as well as cones adequately. This wouldn't be light, even if you went with Baltic Birch ply, perhaps layerd with 1/4" hard board, and solid hardwood corner edges. Baffle step would occur about 800 to 900 Hz. RD would need some EQ in crossover, or you could just crossover at 800 Hz, and LF response of 6-1/2" drivers would be tapered for Baffle step.

      These 6's are rated for 70 W each; even with the power tapering, a realistic rating, figuring normalizing to 140 watts for two in series at 16 ohms, and about 1/3 the impedance with three sets, that's about 420 watts at 6 ohms. Do you think that might play reasonably loud, since the aggregate sensitivity should be at LEAST 90 dB?

      If one watt = 90 db,
      10 watts = 100 dB
      100 watts = 110 dB
      400 watts = 116 dB

      Aw, gee, we better build four, two for surrounds, just to make sure we can hit reference levels....

      Hope your sub has some cajones...



      -Jon

      Comment

      • intelonetwo
        Member
        • Jan 2003
        • 48

        #4
        Thanks Steve, I will check out the drivers you recommended, especially the Vifa which I found a slightly different version at http://www.apexjr.com, called the Vifa P22wp-018 inch drivers for 27.50 each. The tweeter is a tweeter from Tang Bang which can be crossed over as low at 1000hz.




        MI-II-CENTS
        ______________
        The TailWind Generation I

        Comment

        • intelonetwo
          Member
          • Jan 2003
          • 48

          #5
          Hey Steve,
          I looked at the Lambada Acoustics LE drivers that are on sale for $99 for the 15" and $79 for the 12". I am about to buy the Vifa P22WP (4ohm) speakers today along with the Vifa d27tg-45-06 or d26tg-35-06, but I am not sure on which woofers to buy.

          What do you think about them?

          Thomas




          MI-II-CENTS
          ______________
          The TailWind Generation I

          Comment

          • ThomasW
            Moderator Emeritus
            • Aug 2000
            • 10934

            #6
            Jon's recommendation of the MCM drivers is for monopole line array not a TM or MTM dipole configuration.

            Remember that a dipole design usually require ~4 times more radiating area than a monopole design. That's why the Arvo dipole has dual 8"s in addition to dual 10"Titanics.

            FWIW there are almost no tweeters than can be safely used down to 1kHz. We use the Vifa XT25 down to 1.25kHz in the MTM minitower and M8a-MKIV designs. And that's only using one of Jon's high-order XO designs.




            theAudioWorx
            Klone-Audio

            IB subwoofer FAQ page


            "Complicated equipment and light reflectors and various other items of hardware are enough, to my mind, to prevent the birdie from coming out." ...... Henri Cartier-Bresson

            Comment

            • intelonetwo
              Member
              • Jan 2003
              • 48

              #7
              Thanks for the info ThomasW. The design I am talking about is a design similar to the Phoenix, Orion designs, not a monopole. I understand the benefits of a monopole design, however I am not on that project yet. LOL.

              I am trying to design a system that is both cheap in price (approx. $200 per speaker for just raw drivers) and rivals a consumer product at 5 times the cost ($2000 per pair). Since consumer products (Energy, Hales, MK, Monitor Audio, Audio Artistry, etc) have a 5 to 1 ration as far as what materials really cost, I dont think building a design that I am speaking about is out of the question. The workworking and materials will not be a problem since I am very good friends with a cabinet maker and he has all supplies and tools to build with. Also labor is free. The only other expense will be the used crossover (dbx Driverack, or BeringerEQ) and used amplification (6-8 channels). These two costs will be at approx. $1000. Bringing the total to $1400.

              I will be using a Vifa P22WP-01 8" for the mids in a MTM arrangement, a Vifa D26 for the tweeter, and 2 1252DVC in a H-Frame arrangement wired out of phase. This should be a nice low budget system to using more expensive drivers. Any feedback would be great.

              ThomasW sorry I dont know what I was thinking. I would be crossing the tweeter over at the specified 1440 initially, then as testing went on I would tweak this value as needed.

              Any feedback to this is greatly appreciated.

              I know this design is not an Orion Design or Phoenix design and i understand that those designs do sound better, BUT I dont have that kind of money. You hardcore money in the pocket guys, please give me a break. Thanks. Hope to hear from you LOL. :LOL:




              MI-II-CENTS
              ______________
              The TailWind Generation I

              Comment

              • sfdoddsy
                Senior Member
                • Sep 2000
                • 496

                #8
                You might find this site interesting:








                Steve's DIY Dipoles
                Steve's OB Journey

                Comment

                • intelonetwo
                  Member
                  • Jan 2003
                  • 48

                  #9
                  I actually found that link the other day on the Linkwits site Steve, but thanks for the legwork you have been putting in. I do appreciate the help you providing a guy like me who doesnt have the scratch to purchase the big speakers. :LOL:




                  MI-II-CENTS
                  ______________
                  The TailWind Generation I

                  Comment

                  • intelonetwo
                    Member
                    • Jan 2003
                    • 48

                    #10
                    I looked at the Dayton Audio PE 295-310 which has very similiar perfeormance specs as the Seas mid-woofs used in the Phoenix system. I do know that the sound is not going to be the same however as a prototype speaker it will serve as a good starting point. The only real specx difference is the power handling.

                    I am order those mid-range drivers and the tang bang tweeter that is on sale at PE for $12.50. The entire speaker order shouldnt be more than $99.




                    MI-II-CENTS
                    ______________
                    The TailWind Generation I

                    Comment

                    • intelonetwo
                      Member
                      • Jan 2003
                      • 48

                      #11
                      Just thought I would let everyone know that I just order my Dayton AUdio 12" woofers from Parts Express #295-320. They should work out nicely in an H-Frame or W-Frame arrangement.

                      This weekend I plan to build to the H-Frame woofer to mount the woofers on.

                      Also I ordered the Vifa TC18WG-35-09, 7" midrange PE# 299-239, and Peerless tweeter 811815, PE# 277-408. These coupled to the H-frame woofers should give a nice full range output.

                      The entire project costs just under $250.00 for drivers not including materials and labor. Not bad I think for the first time out.
                      Any thoughts.




                      MI-II-CENTS
                      ______________
                      The TailWind Generation I

                      Comment

                      Working...
                      😀
                      😂
                      🥰
                      😘
                      🤢
                      😎
                      😞
                      😡
                      👍
                      👎
                      Searching...Please wait.
                      An unexpected error was returned: 'Your submission could not be processed because you have logged in since the previous page was loaded.

                      Please push the back button and reload the previous window.'
                      An unexpected error was returned: 'Your submission could not be processed because the token has expired.

                      Please push the back button and reload the previous window.'
                      An internal error has occurred and the module cannot be displayed.
                      There are no results that meet this criteria.
                      Search Result for "|||"