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Blue Quarks with a Not-Quite-Voxel subwoofer

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  • Blue Quarks with a Not-Quite-Voxel subwoofer


    Quarks finished in blue veneer with gloss black baffles.

    Then using the PE knockdown 0.23 cubic foot knock down box, a subwoofer. The TB W5-1138 is used with a 1.5" diameter port that is about 12" long in a net volume of about 0.2 cubic feet. The port is L-shaped to fit in the box and the port was flushed into the baffle. Tuned to about 40 Hz in this form. Not quite a Voxel. And I placed a passive 12 db/octave low pass at 100 Hz so that I could power it by the new dayton 2.1 bluetooth amp (which has too high of an active crossover).

    Sounds great!

    I'm happy !!!


    Click image for larger version

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  • #2
    Nice kitchen. That's one heck of a 2.1 system. I had plans to do the same, but sold my quarks due to my wife complaining about too much stereo stuff. I may build them again in the future though.

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    • #3
      Originally posted by Jake View Post
      Nice kitchen. That's one heck of a 2.1 system. I had plans to do the same, but sold my quarks due to my wife complaining about too much stereo stuff. I may build them again in the future though.
      The subwoofer really compliments the Quarks nicely.

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      • #4
        Here’s a better pic showing the blue veneer
        Attached Files

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        • #5
          Inside view
          Attached Files

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          • #6
            This is the passive low pass filter that I used

            https://www.parts-express.com/parts-...sover--266-444

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            • #7
              I will be putting together a micro system for my kitchen and this looks great. I have seen the bantams here and those look slick too.

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              • #8
                That LP filter (9.1mH / 280uF) doesn't affect much below 30Hz, but . . .
                It drops that W5 in YOUR tuned box about -2dB @ 40Hz.
                Close to no effect @ 50.
                @ 60 +1dB
                @ 70-80 +3 to +4dB
                @ 100, +/-0
                @ 200 -12dB - (that's the filter's transfer function)

                So, it actually doesn't do a bad job at rolling the sub's highs off passively.
                The response you end up with peaks around 70Hz.
                F3s are near 60 & 90Hz.
                F6s are near 50 & 110Hz.
                F10s near 40 & 130Hz.

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                • #9
                  Originally posted by Chris Roemer View Post
                  That LP filter (9.1mH / 280uF) doesn't affect much below 30Hz, but . . .
                  It drops that W5 in YOUR tuned box about -2dB @ 40Hz.
                  Close to no effect @ 50.
                  @ 60 +1dB
                  @ 70-80 +3 to +4dB
                  @ 100, +/-0
                  @ 200 -12dB - (that's the filter's transfer function)

                  So, it actually doesn't do a bad job at rolling the sub's highs off passively.
                  The response you end up with peaks around 70Hz.
                  F3s are near 60 & 90Hz.
                  F6s are near 50 & 110Hz.
                  F10s near 40 & 130Hz.

                  thanks for this. As a novice, it helps to learn.

                  Would I be better off just omitting the LP filter?

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                  • #10
                    here is the modeling using the TS parameters of the W5-1138SMF in a 0.2 cubic foot box
                    port of 1.5" x 12" long

                    I tried the sub box without the LP filter and it certainly helps taper down the 100 Hz and above sounds. Without it, there's too much mid-bass (150-200 Hz) in the subwoofer due to the high set point of the active crossover in the 2.1 amp

                    with or without the LP filter, the lower bass (< 100 Hz) sounds the same to me. The modeling with TS parameters doesn't show the values that you calculated above -- so those must be induced (at least in theory) by the LP filter?

                    Click image for larger version

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                    • #11
                      Yes. To model the (textbook?) 2nd order LP filter you used, I took the simmed FR in YOUR box (using WinISD "Pro") and its simmed Z-profile; then applied THAT 9mH series coil and 280uF (? was it) shunt cap in XO sim software. If you're familiar w/the "double-hump" (and valley) Z-curve of a vented box, you can appreciate the wild impedance "roller coaster" that the LP filter is trying to control. It's for those reasons that a passive filter typically won't do a very good job at rolling off the bottom end of a driver (so . . . a "high pass" filter) in the vicinity of its in-box resonance.

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                      • #12
                        Great looking combo.
                        What wood species is your veneer and how did you get the great blue color?
                        andy.

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                        • #13
                          Originally posted by andykriech View Post
                          Great looking combo.
                          What wood species is your veneer and how did you get the great blue color?
                          andy.
                          the blue veneer was from here
                          https://www.dyed-veneer.com/Dyed-Dee...2-1-1-1-2.aspx

                          dyed deep blue kyoto veneer

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                          • #14
                            Beautiful and innovative cosmetics!

                            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

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                            • #15
                              Looks great!

                              IMO my results are not quite as nice as that gorgeous veneer the OP used.

                              But, for those who are interested in a colored stain without tackling the the challenge of veneer... you can get a similar look by staining the wood with Rit Fabric dye, purchased from any WalMart or craft store.

                              It's dead simple to use - simply brush it or rub it on, right out of the bottle. No need to follow the directions on the bottle regarding mixing the dye with hot water, since you're not dying fabric. Once it's fully dry (you may want to wait a few days) rub a wax seal onto it. Rit's advice: https://www.ritdye.com/wood-and-wicker-technique/


                              https://www.flickr.com/photos/johnbo...7660778178773/

                              https://www.flickr.com/photos/johnbo...7660778178773/

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