Announcement

Collapse
No announcement yet.

Active Reference Speaker Project Planning - DIY Tweeters on par with Electrostats?

Collapse
X
  • Filter
  • Time
  • Show
Clear All
new posts

  • Active Reference Speaker Project Planning - DIY Tweeters on par with Electrostats?

    Hello All, it's been awhile since I created a topic. Anyway I am getting into real planning stages for a set of DIY full active reference speakers. 

    Going back to some extended listening sessions I had done a number of years ago with some Martin Logan Prodigy speakers and some B&W 801 & 802 I really enjoyed the open sound of the top end on the MLs but preferred the lower mid/bass dynamics on the B&W.

    I want to try and get the best of both if possible in building a 3 way reference pair.

    There are plenty of high quality woofers/mids available that will provide the uncolored mid/bass range that I am after.

    The tweeter is where I am running into an issue. From what I have read and heard from some others to this point, an air motion transformer/tweeter is probably my best move. I am not opposed to standard dome style tweeters but know that they don't always match that same open/airy capability as a "stat".

    I have been looking a bit closer at actual components for my reference pair of speakers. What are the thoughts on the driver options and how they may pair together?

    Looking initially at a woofer to tweeter crossover point near 2.2Khz and the high pass on the mid/woofer woofer point between 90hz-120hz depending on the woofer choice. The crossover points will come as the final selection is made with drivers. 

    My goal is clean transparent performance from 20-20khz that will give me the open air sound that comes with an electrostatic panel.

    I am open to other suggestions too but I do have to keep a reality check on my budget. Here are a few of the drivers I have been looking into at the moment.

    Tweeter Approx 2.5Khz-20Khz+: Mundorf AMT 23.1M1.1 C

    Mid-woofer options Approx 100hz-2.5Khz: Seas Excel W18E-001 (E0018) 7"
    Or
    Scanspeak Illuminator 18WU/8747T-00, 7" woofer
    Or 
    Dual Dayton Designer series 7" in an MTM?

    Low End approx 20hz-100hz: Dayton Audio Ultimax 10" in a vented high fidelity alignment



    I appreciate the help in advance!

  • #2
    Just wondering aloud here - both the air motion and electrostatic tweeters are dipoles, right? They produce sound in two directions, not just straight ahead.

    It might be that the airy/open sound you hear is a reflection of that.
    Bill Schneider
    -+-+-+-+-
    One word = one milli-picture

    Comment


    • #3
      Ribbons and AMT's do seem to have a bit more of a top end sparkle and air, though try listening to a Be dome if possible.

      The AMT's choice is good and mundorf's is the best and with the current sale a bit reasonable? or try one of the ribbons from RAAL (mega bucks) or viawave(RAAL in a budget? but opinions differ, barring comparison, a very good performing tweeter). I would change the choice of the mid to SS 18M mid as opposed to the 18W or 18WU. for the bottom end, try the dual Dayton Esoteric 7" instead of the classic if you want to stay slim or go big (as in a 10" or bigger woofer).

      Comment


      • #4
        Originally posted by williamrschneider View Post
        Just wondering aloud here - both the air motion and electrostatic tweeters are dipoles, right? They produce sound in two directions, not just straight ahead.

        It might be that the airy/open sound you hear is a reflection of that.
        William's hit the nail in the head.

        When people say they love the open sound of an electrostatic, it is NOT because electrostatics are inherently better sounding than regular speakers. It is because electrostatics are dipoles.

        The dipole radiation pattern is almost entirely responsible for this open sound that you hear, and all the qualities of an electrostatic. A dipole has a radiation pattern of a figure 8. This means sound is radiated from the front and back, but minimally on the side. The rear radiation is responsible for the open sound, because you are hearing a sufficiently delayed and reflected version of the direct sound. I say sufficiently delayed because if it isn't, our brain will interpret that as the same sound as the sound radiated from the front, and it will smear the sound like regular room reflections. Concert halls sound really open exactly because of that. The size of the hall delays the reflected sound sufficiently.

        Electrostatics are also described to have a very detailed, delicate sound. This is almost entirely due to the fact that dipoles have minimal sound radiating to the sides. When you have minimal sound radiating to the side, you minimize the side wall reflections, and you hear much more of the direct sound vs the reflected sound. The side wall reflections smear the direct sound (because it is not sufficiently delayed), and therefore the reduced reflected sound results in a much more detailed sound.

        You can achieve dipole with regular drivers too, it is just that an electrostatic panel will achieve an ideal dipole response naturally due to the flat shape of the membrane, and therefore they naturally do dipole really well. If you want that for your highs, you can still get most of that with regular tweeters if you do it right. Good luck on your research!

        Comment


        • #5
          Well for me the allure of Electrostatic was not due to propagation patterns; There were ( still are ) mono-pole elements for sale ( I bought some in the early 70s), As well as free-standing di-pole panels.
          "Not a Speaker Designer - Not even on the Internet"
          "If the freedom of speech is taken away, then dumb and silent we may be led, like sheep to the slaughter."

          Comment


          • #6
            While I'll concede electrostats/ribbons can offer a diffuse, larger than life soundstage, I do not believe being inherently dipole is the only reason they sound different.

            I have both Carver Amazings, with their 4 12' normal dipole woofers and mid/tweet ribbon, and Apogee Caliper Sigs with separate mid/bass ribbon and tweeter ribbon. Even though they are both dipoles? they sound nothing alike. Among other differences, the Carvers place images in the stage but they're a bit 'big', while the Apogees place everything in the stage with pinpoint accuracy; center, behind the speaker, in front of, outside of, doesn't matter images are sharp as a tac as long as you don't move you head out of the tiny listening window.

            Also, the Apogees have a kind of 'immediacy' to their sound I've heard from no other speaker, no matter their configuration.

            Stereophile review of Caliper https://www.stereophile.com/floorlou...911/index.html

            Stereophile review of Carver Amazing https://www.stereophile.com/floorlou...ver/index.html
            http://techtalk.parts-express.com/fo...khanspires-but
            http://techtalk.parts-express.com/fo...pico-neo-build
            http://techtalk.parts-express.com/fo...ensation-build

            Comment


            • #7
              Originally posted by bcodemz View Post
              William's hit the nail in the head. When people say they love the open sound of an electrostatic, it is NOT because electrostatics are inherently better sounding than regular speakers. It is because electrostatics are dipoles. The dipole radiation pattern is almost entirely responsible for this open sound that you hear, and all the qualities of an electrostatic. A dipole has a radiation pattern of a figure 8. This means sound is radiated from the front and back, but minimally on the side. The rear radiation is responsible for the open sound, because you are hearing a sufficiently delayed and reflected version of the direct sound. I say sufficiently delayed because if it isn't, our brain will interpret that as the same sound as the sound radiated from the front, and it will smear the sound like regular room reflections. Concert halls sound really open exactly because of that. The size of the hall delays the reflected sound sufficiently. Electrostatics are also described to have a very detailed, delicate sound. This is almost entirely due to the fact that dipoles have minimal sound radiating to the sides. When you have minimal sound radiating to the side, you minimize the side wall reflections, and you hear much more of the direct sound vs the reflected sound. The side wall reflections smear the direct sound (because it is not sufficiently delayed), and therefore the reduced reflected sound results in a much more detailed sound. You can achieve dipole with regular drivers too, it is just that an electrostatic panel will achieve an ideal dipole response naturally due to the flat shape of the membrane, and therefore they naturally do dipole really well. If you want that for your highs, you can still get most of that with regular tweeters if you do it right. Good luck on your research!
              But most AMT and ribbon teeters I have seen used in speakers are not used dipole.
              craigk

              " Voicing is often the term used for band aids to cover for initial design/planning errors " - Pallas

              Comment


              • #8
                Originally posted by craigk View Post
                But most AMT and ribbon teeters I have seen used in speakers are not used dipole.
                My understanding, at least for RAAL's, is that they have extremely limited vertical dispersion. I believe that's a major factor why RAAL's sound the way they do. The near elimination of floor and ceiling reflections, which is generally undesirable, produces the remarkably clean and detailed sound that people love.

                Assuming speakers are all of good quality where things like distortion and energy storage issues are not egregious, the difference in radiation pattern is by far the biggest contributor for the large differences of how different types of speaker/driver sound. Every type of distinctive sound that a type of speaker or driver has can be strongly attributed to their radiation pattern. That goes for regular 2 way, 3 way, direct radiator, horns, line arrays, CBTs, all the different style horns, electrostatics, RAAL's, you name it. Each type of speaker/driver listed above have a uniquely different sound that separates them from the rest, and they all have radically different radiation patterns that are the cause of their unique sound character.

                There are certainly other characteristics that contribute to this, namely the various measures of distortion, but they're a lesser contributor. Also, note that within each category, like dipoles, there can be significant differences in radiation pattern between dipoles. Dipoles are notoriously difficult to do right because of how easy it is to impact the radiation pattern with the littlest things. Linkwitz did painstaking work in order to get his dipoles right, and every little detail matters. Same case applies to horns.

                Comment


                • #9
                  Originally posted by craigk View Post
                  But most AMT and ribbon teeters I have seen used in speakers are not used dipole.
                  Agreed - Some Stat builders do not seek dipole response and see it as undesirable, as it mandates large rooms with careful room orientation and constricts placement options.
                  Again for me it was the sonic advantages of a low mass radiator and lower distortion.
                  http://sanderssoundsystems.com/techn...rs-white-paper
                  "Not a Speaker Designer - Not even on the Internet"
                  "If the freedom of speech is taken away, then dumb and silent we may be led, like sheep to the slaughter."

                  Comment


                  • #10
                    Originally posted by bcodemz View Post

                    My understanding, at least for RAAL's, is that they have extremely limited vertical dispersion. I believe that's a major factor why RAAL's sound the way they do. The near elimination of floor and ceiling reflections, which is generally undesirable, produces the remarkably clean and detailed sound that people love.
                    I've been using ribbons since 2004 so I'll comment on vertical dispersion characteristics. You are correct that long ribbons have limited vertical dispersion but shorter ones such as the Fountek CD3.0 Curt and I use in the Statements series are roughly comparable to the vertical dispersion of a one inch dome. Horizontal dispersion of ribbons is superior to domes.

                    Also, we used the Aurum Cantus AST2560 AMT in the Bordeaux and it has the best off axis dispersion of anything I've used not to mention clarity and accuracy.

                    Click image for larger version

Name:	CurveFamily021217.jpg
Views:	1
Size:	81.9 KB
ID:	1341236


                    Comment


                    • #11
                      Go to troels gravesen's website and read what he has to say about the HiVi planar dynamic, which is about $100. He compares it quite favorably to electrostats.

                      Comment


                      • #12
                        Thanks for the replies thus far guys. Appreciated. I have considered a dipole option and am not opposed to it either. The challenge I see is that I would/should also need to di-pole my woofers too, would I not? That will up the price by a fair margin which will push my project outside of my intended budget.

                        I see that there is a dipole version of the Mundorf AMT that I had been considering. The mounting looks interesting on that one though. https://www.madisoundspeakerstore.co...n-tweeter-amt/
                        I assume that it is intended for a flat baffle?

                        I had also had a brief look at the Heil AMTs as well but they are definitely expensive.

                        Thanks for the mentions on the woofers ani.

                        Comment


                        • #13
                          Dayton AMTPRO is dipole capable.
                          Don't waste your money on a new set of speakers, you get more mileage from a cheap pair of sneakers. Next phase, new wave, dance craze, anyways it's still rock and roll to me!

                          Comment


                          • #14
                            Couple of senior people lately have expressed love for the Aurum Cantus AST2560
                            aero striction tweeter. One really nice thing about Parts Exppress is you have 45 days to
                            return a purchase, so no risk. This guy is inherently dipole:

                            https://www.parts-express.com/aurum-...eeter--276-440

                            I think I hear a difference - wow, it's amazing!" Ethan Winer: audio myths
                            "As God is my witness I'll never be without a good pair of speakers!" Scarlett O'Hara

                            High value, high quality RS150/TB28-537SH bookshelf - TARGAS NLA!
                            SB13/Vifa BC25SC06 MTM DCR Galeons-SB13-MTM
                            My Voxel min sub Yet-another-Voxel-build

                            Tangband W6-sub

                            Comment

                            Working...
                            X