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Contemplating my next speaker design, what do you think?

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  • #46
    Re: Contemplating my next speaker design, what do you think?

    Ha! Looks like I missed a lot of replies in this thread and you may have already moved on from your original idea! Happens to me all the time. But, usually when I'm already half way through a project:(

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    • #47
      Re: Contemplating my next speaker design, what do you think?

      Generally edge diffraction is less significant the lower you go in frequency. Since I will be crossing these woofers somewhere below 900hz, I decided that I wanted to trade off the simplicity and contrasting look of a square edge box construction and veneering (as compared to the highly chamfered mid/tweeter baffle) with any edge diffraction that might occur. I suspect there will be little edge diffraction effect in the the passband of these drivers.

      I have not moved on from this design as of yet. I'm just exploring alternatives as folks are mentioning them.;)
      Dan N.

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      • #48
        Re: Contemplating my next speaker design, what do you think?

        Hi Dan,
        OK. I thought that they were using a small tweeter sized woofer producing a 100 hz tone for their tests. It was also mentioned that the bevel had to be a large one, 4 inches I think. Whatever. It might look cool anyway I hope you keep us posted with your progress. You do such excellent work. Good luck with your project. (And your job search.)

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        • #49
          Re: Contemplating my next speaker design, what do you think?

          Hey Dan...your TC1000's are excellent performers in 52L. Ported and tuned to 24hz with 100w input power with an F3 of 29hz and a reasonable port length of 17". Here's the modeled bass response compensating for volume of the port and bracing with a final net volume of 49L.

          Click image for larger version

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          • #50
            Re: Contemplating my next speaker design, what do you think?

            Originally posted by Mayhem13 View Post
            Hey Dan...your TC1000's are excellent performers in 52L. Ported and tuned to 24hz with 100w input power with an F3 of 29hz and a reasonable port length of 17". Here's the modeled bass response compensating for volume of the port and bracing with a final net volume of 49L.

            [ATTACH]3400[/ATTACH]
            I think he's talking about how well the TC1000 can play up to 200-300Hz. THD is an unknown up there, even though the TC plays the first few octaves very well.
            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.

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            • #51
              Re: Contemplating my next speaker design, what do you think?

              This is true! That's why i went with RSS315HF's. BUT if i had some TC's lying around the decision would have been different. Even without some HD sweeps, i'd think the TC1000 can do 250hz no problem.

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              • #52
                Re: Contemplating my next speaker design, what do you think?

                Originally posted by Mayhem13 View Post
                Hey Dan...your TC1000's are excellent performers in 52L. Ported and tuned to 24hz with 100w input power with an F3 of 29hz and a reasonable port length of 17". Here's the modeled bass response compensating for volume of the port and bracing with a final net volume of 49L.

                [ATTACH]3400[/ATTACH]
                Dan's TC drivers are not the standard model. We bought ours from the same OEM source after TC went out of business. The T/S parameters on our drivers are optimized for a sealed sub and won't work well in a vented enclosure unless it was a mass-loaded passive radiator tuned pretty low. I have simulations of each, but I chose to use mine sealed to keep the box small and have been very happy with it. I sent Dan the measurements I took of my driver, his should be pretty much the same. I do not know how well it will reach into the 200's. It has a copper sleeve in the motor and an Le of .73mH, but it has a lot of travel, and with that I wouldn't want to push it too much into midrange frequencies. Then we begin to deal more with Intermodulation Distortion as well.
                Click here for Jeff Bagby's Loudspeaker Design Software

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                • #53
                  Re: Contemplating my next speaker design, what do you think?

                  Originally posted by Jeff B. View Post
                  Dan's TC drivers are not the standard model. We bought ours from the same OEM source after TC went out of business. The T/S parameters on our drivers are optimized for a sealed sub and won't work well in a vented enclosure unless it was a mass-loaded passive radiator tuned pretty low. I have simulations of each, but I chose to use mine sealed to keep the box small and have been very happy with it. I sent Dan the measurements I took of my driver, his should be pretty much the same. I do not know how well it will reach into the 200's. It has a copper sleeve in the motor and an Le of .73mH, but it has a lot of travel, and with that I wouldn't want to push it too much into midrange frequencies. Then we begin to deal more with Intermodulation Distortion as well.
                  Jeff, I have got to ask.

                  What would be your thoughts on the source of IM? Would it be due to Le(x) variations under large excursions?

                  ---------------------------------------------------------------------
                  Too bad that TC is gone, but at least we still have AE!
                  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


                  • #54
                    Re: Contemplating my next speaker design, what do you think?

                    Jeff, I have got to ask.

                    What would be your thoughts on the source of IM? Would it be due to Le(x) variations under large excursions?

                    ---------------------------------------------------------------------
                    Too bad that TC is gone, but at least we still have AE!

                    Actually I probably need to back-track on my statement. IM is generally associated with two-way speakers and not with a woofer working in the frequency range Dan is talking about, so it is much less likely to be an issue. The most common source of IM when it does occur is simply due to a doppler effect from the cone simultaneously making large excursions while also attempting to reproduce midrange frequencies. This affect can be audible in the mids. I don't see Le(x) being much of a concern here since the motor has a full-length copper sleeve and Le is generally very low to start with. I doubt that the change in Le is significant due to the motor design.
                    Click here for Jeff Bagby's Loudspeaker Design Software

                    Comment


                    • #55
                      RSS265HF-RS180x2-MDM55-22TAFG combo

                      Here I go making it more complicated again! :rolleyes:

                      What do you think of this variant? The RSS265HF is in about 65l with a 24" slot port, powered by the 240w dayton plate amp. The box is tuned to about 23hz for an f3 of about 20hz, and gets to about 106db before reaching excursion limits at 200w. I had to close in the back top section to get the bigger volume.

                      The RS180's are sealed. Crossover to the RSS265 in the range of 80-120hz. I would expect the sensitivity to be in the range of 87-89db, depending on BSC, etc.

                      The speaker is still pretty small at 11" wide, 42" tall and 26" deep at the plinth (box is 18" deep)

                      Dan N.

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                      • #56
                        Re: Contemplating my next speaker design, what do you think?

                        That looks like a winner to me, Dan.

                        Comment


                        • #57
                          Re: Contemplating my next speaker design, what do you think?

                          Originally posted by Jed K. View Post
                          That looks like a winner to me, Dan.
                          Ditto!!!

                          4.5-way?
                          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


                          • #58
                            Re: Contemplating my next speaker design, what do you think?

                            I'm working on a similiar design as we speak Dan....couldn't pass up the RSS315 sale! Each cabinet has a single RS315HF sealed in 60L self powered and crossed at 125hz 12db/oct with a pair of SEAS Ca18RLYs sealed in 14L each with an added inductor for a .5 aligment all crossed to a waveguide mounted 27TDFC on a 6.5 waveguide.....top and bottom cabinets are seperate with the .5 midwoofer colocated to the RSS315 in the bottom with a 15 degree slanted baffle. The top cabinet contains the primary midwoofer before the coil and the WG tweeter on a flat baffle since the drivers acoustic centers are already aligned by the depth of the WG. Response should be 25hz to 20khz +/- 2db...i hope. Using your method of joined hardwoods for the baffles.....fiddleback maple and Curly Etimoe with curly maple veneer sides.

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                            • #59
                              Re: Contemplating my next speaker design, what do you think?

                              Ditto!!!

                              4.5-way?
                              I was thinking active plate amp on the RSS265's and a 3 or 3.5way on the remainder. The bottom RS180 is within less than a wavelength at the expected crossover of 800-900 to the MDM55. I may also play with a high pass on the RS180's as I did with the RS150's in the HOSS, or just let them roll off acoustically in their sealed cabinet. I think the mids were cleaner in the HOSS with the high pass included.

                              Originally posted by Mayhem13 View Post
                              I'm working on a similiar design as we speak Dan....couldn't pass up the RSS315 sale! Each cabinet has a single RS315HF sealed in 60L self powered and crossed at 125hz 12db/oct with a pair of SEAS Ca18RLYs sealed in 14L each with an added inductor for a .5 aligment all crossed to a waveguide mounted 27TDFC on a 6.5 waveguide.....top and bottom cabinets are seperate with the .5 midwoofer colocated to the RSS315 in the bottom with a 15 degree slanted baffle. The top cabinet contains the primary midwoofer before the coil and the WG tweeter on a flat baffle since the drivers acoustic centers are already aligned by the depth of the WG. Response should be 25hz to 20khz +/- 2db...i hope. Using your method of joined hardwoods for the baffles.....fiddleback maple and Curly Etimoe with curly maple veneer sides.
                              Sounds like a great project! You should post some drawings, etc. if you have any. I'd like to see what you've come up with.

                              I have on other project I'm considering along with this one. I'm kind of working on that concept a bit more right now that I have the first one roughed out. It would use one of two combo's and would be based upon the concept I posted that is kind of pyramid shaped, very narrow at the top for the tweeter and uses an open backed tube for the midrange. Both concepts would use the TC-1000 as a woofer, probably crossed in the 300-400 range. The mids would be either the 8" PHL 2520 or I would dedicate my Duo cabinets to the Duo-T, which would free up a pair of Scan Revelator 15W/8530K01 for mids. The latter might be a little lower sensitivity design, but with the additional xmax that the TC-1000 and those little Scans have that might not be ok.

                              Pulling the drivers from my Duo-S project would also free up a pair of vifa D26nc55 neo tweeters to use in one of these projects. I'm not sure if this pyramid concept would use the RS28's I have or perhaps the Vifa D26nc55's, since I could get them very close to that 8" mid, maybe doing a shallow waveguide mount for them like in my Duo's and BaSSlines. I already know that the scan and vifa can work well together from using them in my Duo-S design. I'm thinking all passive on this concept, since the Tc-1000's appear to be in the 88-89db sensitivity range. I will put the woofer right down by the floor.

                              I will post more on this latter concept when I get it better thought out. Feedback is welcome, of course.
                              Dan N.

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                              • #60
                                Re: Contemplating my next speaker design, what do you think?

                                The TC-1000-PHL 2520-? tweeter might look something like one of these. I've yet to work out the option with the scan 15w mid:


                                Dan N.

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