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  • #31
    Re: Project L.O.K.I. Build thread.

    yes they do:D this like a great build.
    " To me, the soundstage presentation is more about phase and distortion and less about size. However, when you talk about bass extension, there's no replacement for displacement". Tyger23. 4.2015

    Quote Originally Posted by hongrn. Oct 2014
    Do you realize that being an American is like winning the biggest jackpot ever??

    http://www.midwestaudioclub.com/spot...owell-simpson/
    http://s413.photobucket.com/albums/pp216/arlis/

    Comment


    • #32
      Re: Project L.O.K.I. Build thread.

      Originally posted by ryanbouma View Post
      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?
      Go to options on the measurement section, and choose smoothing instead of gating. I tend to like smoothing. Having it auto-choose gating would tend to bring up some pretty random gating frequencies, so I unchecked that option, so that after the measurement, it's simply raw data. I can then choose how to look at it.
      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


      • #33
        Re: Project L.O.K.I. Build thread.

        Originally posted by arlis_1957@yahoo.com View Post
        yes they do:D this like a great build.
        Also 3 cubic feet?

        Is that dual 8 Ohm, or 4 Ohm?

        Ed wants to make a curved sided cabinet for the TMM, so a simple tapered TL for that one is off, and we'll go for a folded MLTL instead.
        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


        • #34
          Re: Project L.O.K.I. Build thread.

          dual 8ohm. i want to redo them though. designed without measuring. they did measure fairly well at curts but overwhelming bass in this room.
          are you thinking close ctc on the tmm? all mounted high?
          " To me, the soundstage presentation is more about phase and distortion and less about size. However, when you talk about bass extension, there's no replacement for displacement". Tyger23. 4.2015

          Quote Originally Posted by hongrn. Oct 2014
          Do you realize that being an American is like winning the biggest jackpot ever??

          http://www.midwestaudioclub.com/spot...owell-simpson/
          http://s413.photobucket.com/albums/pp216/arlis/

          Comment


          • #35
            Re: Project L.O.K.I. Build thread.

            Originally posted by arlis_1957@yahoo.com View Post
            dual 8ohm. i want to redo them though. designed without measuring. they did measure fairly well at curts but overwhelming bass in this room.
            are you thinking close ctc on the tmm? all mounted high?
            Yeah, I'm thinking the woofers close spaced as possible, making them and the guide stack up to just about 26" total. That means the first woofer will be about 1' off the ground, or about 16" from its center to the floor. I'll probably shoot for about 3dB BSC to start things out, and see how it goes from there. That should put the reference sensitivity right around 88 or 89, a great point for the tweeter and its optimal performance range.
            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


            • #36
              Re: Project L.O.K.I. Build thread.

              Originally posted by cjd View Post
              That's such a potent combo, especially for the price. Every time I go looking for drivers, I spend hours and hours and find myself again looking at the Dayton RS stuff. How do they DO that?
              That was my first thought when I started looking at the PE site...then I came here and got ALL confused.

              :p

              Those waveguides look spectacular!
              https://www.facebook.com/lowecustomguitar

              www.lowecustomguitars.com

              Comment


              • #37
                Re: Project L.O.K.I. Build thread.

                So, the million $ question to me is: how does a tweeter in a waveguide affect imaging? Is it more precise? What happens in the direct comparison between a waveguide loaded and surface mounted tweeter? If on axis response is the same, how does off axis response plays and in which environment it's beneficial?
                http://www.diy-ny.com/

                Comment


                • #38
                  Re: Project L.O.K.I. Build thread.

                  I was thinking about that same thing, fellow sand person!

                  Comment


                  • #39
                    Re: Project L.O.K.I. Build thread.

                    Originally posted by r-carpenter View Post
                    So, the million $ question to me is: how does a tweeter in a waveguide affect imaging? Is it more precise?
                    The waveguide's coverage angle probably makes a difference too. A 120 degree waveguide will probably sound more open (especially without crossfire), a 60 degree waveguide more precise-but-dry, and a 90 deg waveguide somewhere in between.
                    :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


                    • #40
                      Re: Project L.O.K.I. Build thread.

                      :D
                      Originally posted by Thezeek View Post
                      I was thinking about that same thing, fellow sand person!

                      Comment


                      • #41
                        Re: Project L.O.K.I. Build thread.

                        Originally posted by r-carpenter View Post
                        So, the million $ question to me is: how does a tweeter in a waveguide affect imaging? Is it more precise? What happens in the direct comparison between a waveguide loaded and surface mounted tweeter? If on axis response is the same, how does off axis response plays and in which environment it's beneficial?
                        Some of the comments we got on the sound of the ByzyMini/Aurora was a very spacious stage that replicated the sound of a concert hall very admirably. I don't know if they enhance the imaging, or have little impact, but the guides do have a very uniform off axis performance that allows you to literally dial in the amount of high end you prefer, by simply dialing the speaker to a slightly different angle. I'm thinking that as long as you make a really inert cabinet, that imaging should be as good as any point source monitor, maybe even a little better, since everything from 1000Hz on up, where most spatial queues originate, is all in the tweeter.

                        And as I've been reminded previously, a flat baffle is just a 180 degree waveguide.
                        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


                        • #42
                          Re: Project L.O.K.I. Build thread.

                          And here's the response at 0 and 45 degrees. You still think a phase plug is required?
                          Two axial responses do not constitute enough data to determine. And while those two data points you provided look quite good, it is not improbable that they could look better with further degrees of optimization, is it?

                          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.
                          Even though on paper they can hit the numbers, I wouldn't be so sure how that translates to listening reality.

                          When I heard the Statements driven by a big Emotiva amp, I was struck by how compressed they sounded for their size in the upper bass/lower mids. I think there's something to more efficient drivers, i.e. drivers that convert less energy to heat.

                          As for deep bass, who knows, who cares? Anyone who thinks that stereo speakers run full-range sound like music is just acclimated to low-fidelity reproduction in the modal region anyway. The system in which I heard the Statements also featured a double bass array subwoofer setup (8x Dayton Ref 15's, 4 front and 4 back, with each side of the room driven off of channel of a Behringer pro amp) that worked very well.

                          Originally posted by r-carpenter View Post
                          So, the million $ question to me is: how does a tweeter in a waveguide affect imaging?
                          All tweeters are "in waveguides." Flat baffles are just 180deg waveguides. I think a good rule of thumb is that if you can't grip the rim of a midwoofer basket securely between your thumb and index finger, it is unsuitable for use with a tweeter in a 180deg waveguide.

                          With some thought as to waveguide design (as to simply plopping them in a baffle) You can control the angle of the WG to adjust any number of factors relevant to imaging.

                          You can choose the ratio of direct to reflected sound. (Narrower = more direct sound.)

                          You can choose the size of the sweet spot. (Well-designed speakers don't really have a "sweet spot." They have a sweet zone..

                          You can also rotate them to adjust the relative intensity of sidewall reflections (I tend to prefer not lower levels of same-side reflections, and higher levels of contralateral reflections...I think).

                          But most importantly, a WG and directivity match to the driver below it means that the tweeter won't spit at you in the midrange. That spectral infidelity is the main reason why speakers with tweeters on 180deg waveguides all sound so risible, except when the next driver down is very small.
                          --
                          "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


                          • #43
                            Re: Project L.O.K.I. Build thread.

                            Originally posted by Pallas View Post
                            Two axial responses do not constitute enough data to determine. And while those two data points you provided look quite good, it is not improbable that they could look better with further degrees of optimization, is it?



                            Even though on paper they can hit the numbers, I wouldn't be so sure how that translates to listening reality.

                            When I heard the Statements driven by a big Emotiva amp, I was struck by how compressed they sounded for their size in the upper bass/lower mids. I think there's something to more efficient drivers, i.e. drivers that convert less energy to heat.

                            As for deep bass, who knows, who cares? Anyone who thinks that stereo speakers run full-range sound like music is just acclimated to low-fidelity reproduction in the modal region anyway. The system in which I heard the Statements also featured a double bass array subwoofer setup (8x Dayton Ref 15's, 4 front and 4 back, with each side of the room driven off of channel of a Behringer pro amp) that worked very well.



                            All tweeters are "in waveguides." Flat baffles are just 180deg waveguides. I think a good rule of thumb is that if you can't grip the rim of a midwoofer basket securely between your thumb and index finger, it is unsuitable for use with a tweeter in a 180deg waveguide.

                            With some thought as to waveguide design (as to simply plopping them in a baffle) You can control the angle of the WG to adjust any number of factors relevant to imaging.

                            You can choose the ratio of direct to reflected sound. (Narrower = more direct sound.)

                            You can choose the size of the sweet spot. (Well-designed speakers don't really have a "sweet spot." They have a sweet zone..

                            You can also rotate them to adjust the relative intensity of sidewall reflections (I tend to prefer not lower levels of same-side reflections, and higher levels of contralateral reflections...I think).

                            But most importantly, a WG and directivity match to the driver below it means that the tweeter won't spit at you in the midrange. That spectral infidelity is the main reason why speakers with tweeters on 180deg waveguides all sound so risible, except when the next driver down is very small.
                            I've heard people say "ipsilateral" for same-side.

                            Comment


                            • #44
                              Re: Project L.O.K.I. Build thread.

                              Originally posted by Pallas View Post
                              Two axial responses do not constitute enough data to determine. And while those two data points you provided look quite good, it is not improbable that they could look better with further degrees of optimization, is it?
                              Well, here's 20, 45 and 60. The uniformity off axis is as good or better than I've seen. And while I could fuss more over getting an even smoother response from the tweeter, the cost of extra parts to go from +-1.5dB to +-1dB just doesn't seem worth it. The point is, the off axis performance is as good as any other WG, pro or otherwise, that I've seen.



                              Originally posted by Pallas View Post
                              Even though on paper they can hit the numbers, I wouldn't be so sure how that translates to listening reality.

                              When I heard the Statements driven by a big Emotiva amp, I was struck by how compressed they sounded for their size in the upper bass/lower mids. I think there's something to more efficient drivers, i.e. drivers that convert less energy to heat.

                              As for deep bass, who knows, who cares? Anyone who thinks that stereo speakers run full-range sound like music is just acclimated to low-fidelity reproduction in the modal region anyway. The system in which I heard the Statements also featured a double bass array subwoofer setup (8x Dayton Ref 15's, 4 front and 4 back, with each side of the room driven off of channel of a Behringer pro amp) that worked very well.
                              then again, how many people actually have such a ridiculous sub woofer set up, or the space/inclination to build such a thing?

                              90% of the time, the typical user of this system will be using a 150W amp, that can deliver maybe 30W RMS music power without clipping. I doubt that the onset of obvious compression will be hindering their listening experience to any great extent.

                              I'm all for high sensitivity. But that darn reality keeps getting in the way, like space for enclosures, budget, SAF . . .
                              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


                              • #45
                                Re: Project L.O.K.I. Build thread.

                                Well, here's 20, 45 and 60. The uniformity off axis is as good or better than I've seen. And while I could fuss more over getting an even smoother response from the tweeter, the cost of extra parts to go from +-1.5dB to +-1dB just doesn't seem worth it.
                                I agree with that. And at any rate, developing a phase plug that helps more than hurts is probably above the pay grade of most DIY'ers. (Perhaps not you, but certainly me.)

                                then again, how many people actually have such a ridiculous sub woofer set up, or the space/inclination to build such a thing?
                                Actually, that setup didn't take up any apparent space in the room: the front and back walls were false, and the woofers concealed. But that's not the point. The point is that the SPL numbers on paper for the pair of 8's is misleading. In the real world, they're not efficient enough to deliver unconstrained dynamics in the upper bass/lower mids even with oversized amps.

                                Also, you don't seem to understand the point behind the DBA, which is basically to eliminate the effect of room modes on the sound in the modal region. What it gives up compared to other systems using the same number of drive-units is quite a bit of output in the modal region. (In the first-mode region, say maybe from 30-50Hz down depending on the size of the room, they don't give up as much, because they basically all sum in phase.) Hence the need for so much volume displacement.

                                Within the right constraints of room geometry (fairly well sealed rectangle with some furniture restrictions) it works well and can be easily hidden. But yes, for most people (myself included) a DBA is completely impractical. Our rooms aren't perfectly rectangular or particularly well-sealed, we don't have symmetric furniture placement, etc.

                                However, one can do a Geddes-style multisub setup (or a Geddes/Parham hybrid with flanking subs to smooth out floor bounce and randomized placement of three more) in any room that's at least as good as a DBA in terms of modal region response smoothness, and dedicate much less room volume to subs because they're used more efficiently.

                                90% of the time, the typical user of this system will be using a 150W amp, that can deliver maybe 30W RMS music power without clipping. I doubt that the onset of obvious compression will be hindering their listening experience to any great extent.
                                I guess it depends on what one is used to.

                                I'm all for high sensitivity. But that darn reality keeps getting in the way, like space for enclosures, budget, SAF . . .
                                There's an obvious answer to that. Pick a different point on the Hoffmann's Iron law continuum: more efficiency, less extension, similar size. And use multisubs strategically hidden in the room to blend with the mains in the modal region and provide the foundation. For instance, instead of using a pair of Dayton 8's, try B&C 8NDL51's. (Or the cheaper ferrite-magnet ones, though I've only personally played with the neo ones.) Even if they only get to 100Hz or so on paper, in practice when blended with a multisub system the results will be smoother response.
                                --
                                "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

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