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RE: [dallasaudioclub] Measuring loudspeaker parameters

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  • Dave Thomas
    For anyone who might be interested I have a complete loudspeaker measurement system and can test any driver you like for T/S parameter, and impedance and
    Message 1 of 8 , Jan 13, 2008

      For anyone who might be interested I have a complete loudspeaker measurement system and can test any driver you like for T/S parameter, and impedance and frequency response measurements including tweeters, I can provide impedance and frequency response plots both graphically and as .frd or .zma files for use in modeling software. I also do multi-way crossover and enclosure designs including dipole and line array systems.

       

      So if you have vintage drivers you would like tested or any driver that you don’t know the parameters for let me know I am always glad to help. I have done a lot of designs including designs for major consumer manufacturers. I do audio now as a hobby so my time is limited but I am always interested in a new project. I have several new projects that are being built one is a high end 2 way monitor using Usher and Peerless HDS drivers, a 3 way dipole midrange design and a short array for home theatre that I personally just completed and a large 3 way using a 9 woofer array and the BG NEO8 for a midrange and a Vifa XT25 ring radiator tweeter. The latter will be a high efficiency, high spl project it is being built by friend here in Dallas .

       

      Dave

       


      From: dallasaudioclub@yahoogroups.com [mailto: dallasaudioclub@yahoogroups.com ] On Behalf Of V.G.B.
      Sent: Sunday, January 13, 2008 7:03 PM
      To: dallasaudioclub@yahoogroups.com
      Subject: [dallasaudioclub] Measuring loudspeaker parameters

       

      I meant to post a short write-up about this and finally got around to doing it. Hope this helps someone. Especially useful for vintage drivers where T/S parameters aren't available.

      http://zobsky. blogspot. com/2008/ 01/simple- loudspeaker- measurement- jig-for.html

       


      Never miss a thing. Make Yahoo your homepage.

    • Dave Thomas
      http://tech.ph.groups.yahoo.com/group/dallasaudioclub/photos/browse/799a Here is a link to the latest mini arrays I built for a personal Home Theater project.
      Message 2 of 8 , Jan 13, 2008

        http://tech.ph.groups.yahoo.com/group/dallasaudioclub/photos/browse/799a

         

        Here is a link to the latest mini arrays I built for a personal Home Theater project. They are very dynamic and project a very 3D soundstage. Fun project just have to cut a lot of holes and wire a lot of of drivers up so it was very time consuming. I also included the measured frequency response they turned out quite well and I was able to push any comb filtering out to around 11KHz which was mild at best. Notice how tightly spaced the 9 tweeters are.

         

        Dave

         


        From: dallasaudioclub@yahoogroups.com [mailto: dallasaudioclub@yahoogroups.com ] On Behalf Of V.G.B.
        Sent: Sunday, January 13, 2008 7:03 PM
        To: dallasaudioclub@yahoogroups.com
        Subject: [dallasaudioclub] Measuring loudspeaker parameters

         

        I meant to post a short write-up about this and finally got around to doing it. Hope this helps someone. Especially useful for vintage drivers where T/S parameters aren't available.

        http://zobsky. blogspot. com/2008/ 01/simple- loudspeaker- measurement- jig-for.html

         


        Never miss a thing. Make Yahoo your homepage.

      • Richard Rea
        Very nicely done. I hope to get started on my first project very soon. Have the driver s, WT2, design software, and a plan for a MTM in a vented 6 cu ft box.
        Message 3 of 8 , Jan 14, 2008
          Very nicely done.
          I hope to get started on my first project very soon.
          Have the driver's, WT2, design software, and a plan
          for a MTM in a vented 6 cu ft box. Kinda large but I
          all ready have the drivers.

          Richard

          --- Dave Thomas <dthomas@...> wrote:

          >
          http://tech.ph.groups.yahoo.com/group/dallasaudioclub/photos/browse/799a
          >
          >
          >
          > Here is a link to the latest mini arrays I built for
          > a personal Home
          > Theater project. They are very dynamic and project a
          > very 3D soundstage.
          > Fun project just have to cut a lot of holes and wire
          > a lot of of drivers
          > up so it was very time consuming. I also included
          > the measured frequency
          > response they turned out quite well and I was able
          > to push any comb
          > filtering out to around 11KHz which was mild at
          > best. Notice how tightly
          > spaced the 9 tweeters are.
          >
          >
          >
          > Dave
          >
          >
          >
          > ________________________________
          >
          > From: dallasaudioclub@yahoogroups.com
          > [mailto:dallasaudioclub@yahoogroups.com] On Behalf
          > Of V.G.B.
          > Sent: Sunday, January 13, 2008 7:03 PM
          > To: dallasaudioclub@yahoogroups.com
          > Subject: [dallasaudioclub] Measuring loudspeaker
          > parameters
          >
          >
          >
          > I meant to post a short write-up about this and
          > finally got around to
          > doing it. Hope this helps someone. Especially useful
          > for vintage drivers
          > where T/S parameters aren't available.
          >
          >
          http://zobsky.blogspot.com/2008/01/simple-loudspeaker-measurement-jig-fo
          > r.html
          >
          <http://zobsky.blogspot.com/2008/01/simple-loudspeaker-measurement-jig-f
          > or.html>
          >
          >
          >
          > ________________________________
          >
          > Never miss a thing. Make Yahoo your homepage.
          >
          <http://us.rd.yahoo.com/evt=51438/*http:/www.yahoo.com/r/hs>
          >
          >
          >
          >
          >


          Richard Rea
          a man of few words :)
        • Dave Thomas
          Wow... 6 cubic feet. What are the woofers that is a huge cabinet? I have a WT2 also great little tool. Dave ________________________________ From:
          Message 4 of 8 , Jan 14, 2008

            Wow… 6 cubic feet. What are the woofers that is a huge cabinet? I have a WT2 also great little tool.

             

            Dave

             


            From: dallasaudioclub@yahoogroups.com [mailto: dallasaudioclub@yahoogroups.com ] On Behalf Of Richard Rea
            Sent: Monday, January 14, 2008 8:50 AM
            To: dallasaudioclub@yahoogroups.com
            Subject: RE: [dallasaudioclub] Measuring loudspeaker parameters

             

            Very nicely done.
            I hope to get started on my first project very soon.
            Have the driver's, WT2, design software, and a plan
            for a MTM in a vented 6 cu ft box. Kinda large but I
            all ready have the drivers.

            Richard

            --- Dave Thomas <dthomas@turinnetwor ks.com> wrote:

            >
            http://tech. ph.groups. yahoo.com/ group/dallasaudi oclub/photos/ browse/799a
            >
            >
            >
            > Here is a link to the latest mini arrays I built for
            > a personal Home
            > Theater project. They are very dynamic and project a
            > very 3D soundstage.
            > Fun project just have to cut a lot of holes and wire
            > a lot of of drivers
            > up so it was very time consuming. I also included
            > the measured frequency
            > response they turned out quite well and I was able
            > to push any comb
            > filtering out to around 11KHz which was mild at
            > best. Notice how tightly
            > spaced the 9 tweeters are.
            >
            >
            >
            > Dave
            >
            >
            >
            > ____________ _________ _________ __
            >
            > From: dallasaudioclub@ yahoogroups. com
            > [mailto:dallasaudioclub@ yahoogroups. com]
            On Behalf
            > Of V.G.B.
            > Sent: Sunday, January 13, 2008 7:03 PM
            > To: dallasaudioclub@ yahoogroups. com
            > Subject: [dallasaudioclub] Measuring loudspeaker
            > parameters
            >
            >
            >
            > I meant to post a short write-up about this and
            > finally got around to
            > doing it. Hope this helps someone. Especially useful
            > for vintage drivers
            > where T/S parameters aren't available.
            >
            >
            http://zobsky. blogspot. com/2008/ 01/simple- loudspeaker- measurement- jig-fo
            > r.html
            >
            <http://zobsky. blogspot. com/2008/ 01/simple- loudspeaker- measurement- jig-f
            > or.html>
            >
            >
            >
            > ____________ _________ _________ __
            >
            > Never miss a thing. Make Yahoo your homepage.
            >
            <http://us.rd. yahoo.com/ evt=51438/ *http:/www. yahoo.com/ r/hs>
            >
            >
            >
            >
            >

            Richard Rea
            a man of few words :)

          • Richard Rea
            Oh no, my WT2 dose not work:( can t calibrate it just show 32ohms. The speakers are 8 Zetag wofers. I was told they work great in a 3cu ft box vented. So, I
            Message 5 of 8 , Jan 14, 2008
              Oh  no, my WT2 dose not work:( can't calibrate it just show 32ohms.
              The speakers are 8" Zetag wofers. I was told they work great in a 3cu ft box vented. So, I figure 2 for an mtm would be 6cu ft. I have not modled it yet and looks like it's on hold pending testing.
              Tweeter is a Fountek Ribion. Think I spelled that right.
               
              Richard

              Dave Thomas <dthomas@...> wrote:
              Wow… 6 cubic feet. What are the woofers that is a huge cabinet? I have a WT2 also great little tool.
              Dave

              From: dallasaudioclub@ yahoogroups. com [mailto: dallasaudioclub@ yahoogroups. com ] On Behalf Of Richard Rea
              Sent: Monday, January 14, 2008 8:50 AM
              To: dallasaudioclub@ yahoogroups. com
              Subject: RE: [dallasaudioclub] Measuring loudspeaker parameters
              Very nicely done.
              I hope to get started on my first project very soon.
              Have the driver's, WT2, design software, and a plan
              for a MTM in a vented 6 cu ft box. Kinda large but I
              all ready have the drivers.

              Richard

              --- Dave Thomas <dthomas@turinnetwor ks.com> wrote:

              >
              http://tech. ph.groups. yahoo.com/ group/dallasaudi oclub/photos/ browse/799a
              >
              >
              >
              > Here is a link to the latest mini arrays I built for
              > a personal Home
              > Theater project. They are very dynamic and project a
              > very 3D soundstage.
              > Fun project just have to cut a lot of holes and wire
              > a lot of of drivers
              > up so it was very time consuming. I also included
              > the measured frequency
              > response they turned out quite well and I was able
              > to push any comb
              > filtering out to around 11KHz which was mild at
              > best. Notice how tightly
              > spaced the 9 tweeters are.
              >
              >
              >
              > Dave
              >
              >
              >
              > ____________ _________ _________ __
              >
              > From: dallasaudioclub@ yahoogroups. com
              > [mailto:dallasaudioclub@ yahoogroups. com] On Behalf
              > Of V.G.B.
              > Sent: Sunday, January 13, 2008 7:03 PM
              > To: dallasaudioclub@ yahoogroups. com
              > Subject: [dallasaudioclub] Measuring loudspeaker
              > parameters
              >
              >
              >
              > I meant to post a short write-up about this and
              > finally got around to
              > doing it. Hope this helps someone. Especially useful
              > for vintage drivers
              > where T/S parameters aren't available.
              >
              >
              http://zobsky. blogspot. com/2008/ 01/simple- loudspeaker- measurement- jig-fo
              > r.html
              >
              <http://zobsky. blogspot. com/2008/ 01/simple- loudspeaker- measurement- jig-f
              > or.html>
              >
              >
              >
              > ____________ _________ _________ __
              >
              > Never miss a thing. Make Yahoo your homepage.
              >
              <http://us.rd. yahoo.com/ evt=51438/ *http:/www. yahoo.com/ r/hs>
              >
              >
              >
              >
              >

              Richard Rea
              a man of few words :)



              Richard Rea
              a man of few words :)
            • Fred
              ... soundstage. Nice looking speakers, Dave! I would like to know more about them. Would you consider posting a summary (drivers used, crossover, etc) on the
              Message 6 of 8 , Jan 21, 2008
                --- In dallasaudioclub@yahoogroups.com, "Dave Thomas" <dthomas@...>
                wrote:
                > Here is a link to the latest mini arrays I built for a personal Home
                > Theater project. They are very dynamic and project a very 3D
                soundstage.

                Nice looking speakers, Dave! I would like to know more about them.
                Would you consider posting a summary (drivers used, crossover, etc) on
                the Audio Circle Line Array forum?
              • Dave Thomas
                I could do that I have been quite busy but it is possible. It is not a near-field array. I designed the crossover to minimize combing above 10KHz and based the
                Message 7 of 8 , Jan 21, 2008

                  I could do that I have been quite busy but it is possible. It is not a near-field array. I designed the crossover to minimize combing above 10KHz and based the crossover design on a flat response if the listener is sitting at the transition from near to far field. The optimized listening distance is around 3 meters. It resulted in a very flat measured response with very minimal combing occurring at above 11KHz. The response above 10K was slightly tilted to offset any apparent loss in this region. The crossover is passive and very simple I used the acoustic slopes of the drivers to get better than 3rd order slopes with a 2nd and 3rd order electrical filter. There are only 6 components including a padding resistor for the tweeter comprising the crossover. By using the roll off created by combing on the woofer array I was able to get a fairly steep slope with just two components and avoid any combing in the woofer line. I used the Hivi A3SII midwoofer but it could be done with the B3SII.

                   

                  All in all they are very nice sounding and dynamic. I cross them to a sub electronically at 120Hz. I am completing a matching center channel that uses 6 of the 3” midwoofers , 3 on each side splayed in about 10 degrees with a line of 3 tweeters in the center. The woofer are mounted in a traditional horizontal fashion at least traditional for center channels and the the tweeter are stacked vertically in the center to optimize dispersion and create a wider radiation pattern for the horizontal woofers. After I complete this I can post the final project.

                   

                  The first is a blown up measured response (1db), the second is a more conventional graph on a less resolved graph looks more impressive and includes a better gated response for the tweeter that eliminated from reflection issues in the first measurement so it is more representative of an anechoic response. The last is the impedance profile it is a fairly benign and is easy to drive.

                   

                  Dave

                   


                  From: dallasaudioclub@yahoogroups.com [mailto: dallasaudioclub@yahoogroups.com ] On Behalf Of Fred
                  Sent: Monday, January 21, 2008 5:59 PM
                  To: dallasaudioclub@yahoogroups.com
                  Subject: [dallasaudioclub] Re: Measuring loudspeaker parameters

                   

                  --- In dallasaudioclub@ yahoogroups. com, "Dave Thomas" <dthomas@... >
                  wrote:

                  > Here is a link to the latest mini arrays I built for a personal Home
                  > Theater project. They are very dynamic and project a very 3D
                  soundstage.

                  Nice looking speakers, Dave! I would like to know more about them.
                  Would you consider posting a summary (drivers used, crossover, etc) on
                  the Audio Circle Line Array forum?

                Your message has been successfully submitted and would be delivered to recipients shortly.