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  • #16
    Re: Project L.O.K.I. Build thread.

    Originally posted by Erich H View Post
    Does anyone have a CAD file or proper curves of the waveguide? I could ask the company that prototyped the SEOS waveguide and see if they could make up some for this particular tweeter.
    DanP drew it up in the DIY waveguide thread. I don't know if the file he created is suitable for other CNC machines to use. The profile is pretty much circular, with maybe a 3.5" radius, or close to that.

    You might PM DanP and see if he has a file that you can use.
    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


    • #17
      Re: Project L.O.K.I. Build thread.

      I searched for "DIY waveguide", and I must be blind because I can't find the thread. I remember reading it, but can't seem to locate it. But I will continue searching.

      Comment


      • #18
        Re: Project L.O.K.I. Build thread.

        Originally posted by Erich H View Post
        I searched for "DIY waveguide", and I must be blind because I can't find the thread. I remember reading it, but can't seem to locate it. But I will continue searching.
        http://techtalk.parts-express.com/sh...d.php?t=223719
        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


        • #19
          Re: Project L.O.K.I. Build thread.

          Well, since you already determined it was going to be a tapered TL, I was sure you had completed the TL design.:p

          Your proposed cabinet dimensions and volume as well as the taper ratio sound about right, at least for the 8-ohm version, for the intended F3. I'll let you have all the modeling fun, however, as I've got plenty of modeling on my plate for others right now.
          Paul

          You know what they say about assuming don't you? :D

          No, haven't done any modeling yet. I want to actually get the drivers in hand and measure. I'm still not even sure which version of the RS225 Ed has, the 4 or 8 Ohm.

          But overall, I think the enclosure will be around 2 cubic feet based on the published specs. That would put the depth of the enclosure at around 13" with a single fold. I'm guessing that with that geometry, a slot port maybe 8" x .875" at the top/back should get me a ~14:1 taper. and again, guessing this will be about right for an F3 of around 30Hz.

          I'll have to run it through the worksheets to confirm . . . unless you want to. ;)

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          • #20
            Re: Project L.O.K.I. Build thread.

            Well, here we go again. A 2-way with 8" woofer and waveguide loaded tweeter build thread . . . :rolleyes:
            Is there any real advantages to a flat baffle 99% of the time? The only one I see is that it's easier. So IMO there's nothing played out about it...
            :blues: Flat frequency response, a smooth sound power response free of resonance, careful driver-integration, and high dynamic range both upward and downward :blues:

            Comment


            • #21
              Re: Project L.O.K.I. Build thread.

              But overall, I think the enclosure will be around 2 cubic feet based on the published specs. That would put the depth of the enclosure at around 13" with a single fold. I'm guessing that with that geometry, a slot port maybe 8" x .875" at the top/back should get me a ~14:1 taper. and again, guessing this will be about right for an F3 of around 30Hz.

              I'll have to run it through the worksheets to confirm . . . unless you want to. ;)
              Hmmm... Well, that's what I get for never finishing a project, someone else doing it instead! :eek: :o

              Looks like you're going to use a 8" PE waveguide, I had been contemplating the 6.5" Pyle/MCM one that Zaph was carving up, back when. The 8" might be a better choice. A lot seems to depend on the picky results of how the guide and a particular tweeter go together.

              PaulK, also way back when, modeled me up a nice RS225 TL box... (thanks again, and apologies that I never built it!) have to dig that up and see how close yours is... sounds very familiar.

              Should be a nice speaker!!

              Comment


              • #22
                Re: Project L.O.K.I. Build thread.

                Originally posted by GranteedEV View Post
                Is there any real advantages to a flat baffle 99% of the time? The only one I see is that it's easier. So IMO there's nothing played out about it...
                Well, I was being a little bit facetious in my opening line. ;)

                Got a lot more playing to do with these waveguides.

                After this, I'm seriously contemplating a 12" 2-way using the Eminence 3012LF with this guide in a 3 cubic foot floor stander, Econowave Deluxe but with a dome tweeter instead of the compression driver and 15" QSC guide. This dome/guide combo is a natural for 1KHz XO points. The DE250 and QSC guide only let you get to 1500. Granted, it won't play to the same peak levels as the DE250, but for most folks, it will play loud enough to meet the need, and play quite a bit smoother 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


                • #23
                  Re: Project L.O.K.I. Build thread.

                  Originally posted by jonpike View Post
                  Hmmm... Well, that's what I get for never finishing a project, someone else doing it instead! :eek: :o

                  Looks like you're going to use a 8" PE waveguide, I had been contemplating the 6.5" Pyle/MCM one that Zaph was carving up, back when. The 8" might be a better choice. A lot seems to depend on the picky results of how the guide and a particular tweeter go together.

                  PaulK, also way back when, modeled me up a nice RS225 TL box... (thanks again, and apologies that I never built it!) have to dig that up and see how close yours is... sounds very familiar.

                  Should be a nice speaker!!
                  Not the PE waveguide, but a custom guide that Ed will be cutting into the MDF. It's an absolute perfect match to the RS28F/A and perhaps some other tweeters with the same flange opening size.

                  Here's a picture of some smaller baffles he's already made for other folks. It's the same profile we used in the Aurora/MiniByzy.



                  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


                  • #24
                    Re: Project L.O.K.I. Build thread.

                    After this, I'm seriously contemplating a 12" 2-way using the Eminence 3012LF with this guide in a 3 cubic foot floor stander, Econowave Deluxe but with a dome tweeter instead of the compression driver and 15" QSC guide. This dome/guide combo is a natural for 1KHz XO points. The DE250 and QSC guide only let you get to 1500. Granted, it won't play to the same peak levels as the DE250, but for most folks, it will play loud enough to meet the need, and play quite a bit smoother too.
                    The only dome tweeters I've ever heard sound as smooth as a B&C or BMS compression driver (with proper crossover) are the KEF units with their 8-spoke ("Tangerine") phase plug and the Tannoy units with their multi-ring ("Tulip") phase plug.

                    What those two have in common with the compression drivers is a phase plug developed for their specific applications. Otherwise, I see nothing special about either firm's dome tweeters.

                    True, domes in controlled waveguides with well-executed crossovers do generally sound much better than domes on 180 deg waveguides (i.e. flat baffles). But I suspect that wringing the nth degree of performance out of them will ultimately require a phase plug designed to load it into a waveguide.
                    --
                    "Based on my library and laboratory research, I have concluded, as have others, that the best measures of speaker quality are frequency response and dispersion pattern. I have not found any credible research showing that most of the differences we hear among loudspeakers cannot be explained by examining these two variables." -Alvin Foster, 22 BAS Speaker 2 (May, 1999)

                    Comment


                    • #25
                      Re: Project L.O.K.I. Build thread.

                      Originally posted by Pallas View Post
                      The only dome tweeters I've ever heard sound as smooth as a B&C or BMS compression driver (with proper crossover) are the KEF units with their 8-spoke ("Tangerine") phase plug and the Tannoy units with their multi-ring ("Tulip") phase plug.

                      What those two have in common with the compression drivers is a phase plug developed for their specific applications. Otherwise, I see nothing special about either firm's dome tweeters.

                      True, domes in controlled waveguides with well-executed crossovers do generally sound much better than domes on 180 deg waveguides (i.e. flat baffles). But I suspect that wringing the nth degree of performance out of them will ultimately require a phase plug designed to load it into a waveguide.
                      Well, looking at the actual response plots of the RS28 in that guide would suggest that no phase plug is required.

                      Here's the final response plot of the NE225W/RS28F



                      And here's the response at 0 and 45 degrees. You still think a phase plug is required?

                      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


                      • #26
                        Re: Project L.O.K.I. Build thread.

                        In my Alicante 3-way that I built in 2006, the RS225S-8 is in an 18:1 tapered TL with a line volume right at 2 ft3 and an F3 of 32 Hz. If you compare the published specs for the RS225S-8 and current RS225-8, you'll see they're very close, so that's why I think Pete's thinking should be just about right.
                        Paul

                        Originally posted by jonpike View Post
                        Hmmm... Well, that's what I get for never finishing a project, someone else doing it instead! :eek: :o

                        Looks like you're going to use a 8" PE waveguide, I had been contemplating the 6.5" Pyle/MCM one that Zaph was carving up, back when. The 8" might be a better choice. A lot seems to depend on the picky results of how the guide and a particular tweeter go together.

                        PaulK, also way back when, modeled me up a nice RS225 TL box... (thanks again, and apologies that I never built it!) have to dig that up and see how close yours is... sounds very familiar.

                        Should be a nice speaker!!

                        Comment


                        • #27
                          Re: Project L.O.K.I. Build thread.

                          OK, I installed the RS28A onto the back of the raw, unsanded baffle Ed rushed to me. He was "curious" if the unsmooth surface was of any benefit . . . :rolleyes:

                          So, I ran a plot after making sure I had a smooth throat area with a little fine sanding just down there. 6th octave smoothing. That little blip around 18000 will probably be gone with a touch more sanding down in the interface area between flange and guide.

                          I also noticed that there's a slight reduction in the top octave between the flat baffle vs waveguide mounted tweeters. Look at the 14000Hz frequency below to see the reference frequency where no-waveguide matches in-waveguide. From that point down, the guide is lifting 10dB and more, to below 1000Hz.

                          After EQ'ing this to match the RS225, distortion levels should be hugging the -55dB line, which is my current noise floor, to below 1000Hz. It should be able to keep up with even a pair of RS225 with a 2nd order HP between 800 and 1000Hz. :D


                          This looks very workable. Sorry, no woofer data yet. Ed didn't send me his RS225-4, and we're thinking about a TMM 2.5-way version.

                          Hey Mike, this should work for your big ten inch!


                          Last edited by Pete Schumacher; 01-03-2012, 08:47 PM.
                          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


                          • #28
                            Re: Project L.O.K.I. Build thread.

                            I was doing a little modeling of vented enclosures for a pair of RS225, TMM style, and found that a 3 cf enclosure with a mid 30s tune will allow one enclosure to reach 110dB from mid 30s and up, within Xmax. No wonder the Exclamation, Statement and Khanspire systems can pound out the bass.

                            These may give the Econowave's a run for the money.
                            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


                            • #29
                              Re: Project L.O.K.I. Build thread.

                              Yes!!! This is something that I've been waiting for, particularly it TMM version. I think it would make a good klipsch rf "clone", kinda. I'm sure this will far surpass the rf5

                              Dan

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                              • #30
                                Re: Project L.O.K.I. Build thread.

                                Pete, sorry for the OT question here... (great build so far btw).

                                Is there a way to smooth a gated response in HolmImpulse? I see you smoothed that last response, but did you not gate, or how did you do that?
                                https://www.youtube.com/channel/UCm2...oSKdB448TTVEnQ

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