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Translam Subwoofers with 18" Passive Radiators - The Jedi Mind Tricks

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  • Originally posted by JavadS View Post
    Looking good Keith! I've been applying poly to stuff since the late 80's and at some point reverted to either spray cans or a spray gun and haven't looked back. The uniformity of spray is very tough to duplicate with any other technique I've found or have the skill or patience to pull off.
    Thanks Javad!

    One day I may pick up an HVLP turbine system (or go big and get a decent compressor!) and try spraying things. Going with rattle can methods gets majorly expensive when buying one or two cans at a time at the hardware store. I figured wipe on poly was worth a try, and has been an interesting experiment. I think it has it's place in the world, but only if I allow myself to be OK with the occasional run or goof up! Ultimately, quality craftsmanship is the goal, so spray-on methods are in the future.
    Voxel Down Firing with Dayton SA70
    Translam Subwoofers - The Jedi Mind Tricks

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    • Tonight I started the subwoofer break-in process. I took some ideas on mounting the sub in free air from youtube (123Toid's channel, who I suspect is tech talk forum member Altoid, but I've not confirmed that. Thanks anyway!) To make this happen I had to unhook my Crown XLS 1002 from the current Ultimax15 that's in the living room and take it to my evil speaker testing laboratory (AKA, the guest room).

      I used Audacity to generate a 20-50Hz sine sweep and loop it at full reference output (a "1" on an output scale of 0-1). That was being fed to my Marantz SR6006 receiver, which was set to 0dB volume and +0dB channel level for the subwoofer. Under these settings, I could push the crown amp up to about 2 o'clock before I got any nasty excursion limit sounds from the RSS315HF-4 subwoofer. Wiring wise, I doubled up on 14AWG wire to make ~11AWG hookup between the Crown and the subwoofer. I'll let this run while I'm at work tomorrow at half tilt. I'd worry about going full out while I'm not there to monitor just in case it limbers up and started to reach Xmax under the same power load. I can't allow that!

      Otherwise, wiithout anything playing, this subwoofer in free air is the first time I've heard the amplifier noise floor on the Crown. I had to put my ear almost directly on the cone to pick it up, but it was there. I'll never hear that in practice, so no worries.

      Here's a fancy flex test picture and some video!

      Click image for larger version

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      Voxel Down Firing with Dayton SA70
      Translam Subwoofers - The Jedi Mind Tricks

      Comment


      • You're spot on. I am 123Toid on YouTube. I see the latest video, do you need to break in a subwoofer was help. I'm glad it helped. That video you posted is pretty awesome! I'm glad the free air helped you break in the subwoofer.
        All about Speaker Design YouTube Channel

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        • Hey Everyone,
          It almost sounds odd to say this, but the cabinet construction phase is DONE!

          Tonight I put the mattress topper foam lining in both cabinets and installed the SpeakON connectors in the rear of the cabinet. That was the last step in the not-so-basic construction of these cabinets, so soon I can get around to making the walls shake! I have one subwoofer thoroughly broken in at this point. I left it running all day while I was at work doing 20-50 Hz sweeps at moderate volume. I'll be taking an "after" DATS measurement for comparison, and to plug it back into BassBox to confirm my expected passive radiator tuning.

          Once I get both drivers broken in, I'll mount the passive radiators backwards (mass hanging out) while I play with the washers. This way I don't have to constantly take the PR out every time I need to adjust the mass. I also have another 2-pole speakon connector coming in the mail that I will use as a DATS hookup while the subwoofer is installed in the cabinets (no port holes to fish wires through!) This should let me confirm the tuning before locking everything down and starting the room EQ process with the OmniMic and MiniDSP.

          It's about time I got to play with the engineering tools instead of the woodworking tools! Can't wait to get this rolling!

          Click image for larger version

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          Voxel Down Firing with Dayton SA70
          Translam Subwoofers - The Jedi Mind Tricks

          Comment


          • Yeah man, nice job, those look stellar!
            A mains
            The Ventures
            Open Invit8tions
            RSR
            Sound Troopers
            Acorns
            442
            DGBG's
            The Monuments

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            • Very nice work Keith! Awesome attention to detail, they look amazing! Javad
              --
              Javad Shadzi
              Bay Area, CA

              2-Channel Stereo system in the works with Adcom components and 4-way towers

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              • Good evening, gents

                The official changing of the guard has occurred, and the Jedi Mind Tricks are now sitting proudly in the front of my living room! This tickles my engineering symmetry funny bone, and I can't wait to get these things powered up and start learning some Room EQ with OmniMic and MiniDSP!

                Honestly, the more I look at these things, the more I feel like I'm on the wrong end of a cannon. Scary in a good way! Whenever I get to the point where I can do some bass testing, my phone won't do it justice. I'll just have to show you videos of things rattling all over .

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                Voxel Down Firing with Dayton SA70
                Translam Subwoofers - The Jedi Mind Tricks

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                • Congratulations - those will bring many smiles for years to come. Beautiful job and top notch woodworking.

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                  • So the sub baffles match your mains and center... don't know if you stated that already way up /|\ there in yonder nether posts that that was what you were going for, but it really looks good.

                    How is the low stuff on those? You need to put a movie sound track on those and let 'er rip.....
                    Man, you've got to smile each time you look at those in that room. Those things are awesome.

                    Making your stuff look SO good is a great way to get the wife on board... well yours already is... but keep her on board. Well done!

                    TomZ
                    *Veneering curves, seams, using heat-lock iron on method *Trimming veneer & tips *Curved Sides glue-up video
                    *Part 2 *Gluing multiple curved laminations of HDF *Cello's Speaker Project Page

                    *Building the "Micro-B 2.1 Plate Amplifier -- Part 1 * Part 2 * Part 3 * Part 4 * * Part 5 'Review' * -- Assembly Instructions PDF

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                    • Originally posted by tomzarbo View Post
                      So the sub baffles match your mains and center... don't know if you stated that already way up /|\ there in yonder nether posts that that was what you were going for, but it really looks good.

                      How is the low stuff on those? You need to put a movie sound track on those and let 'er rip.....
                      Man, you've got to smile each time you look at those in that room. Those things are awesome.

                      Making your stuff look SO good is a great way to get the wife on board... well yours already is... but keep her on board. Well done!

                      TomZ
                      Thanks Tom! I didn't intentionally try to match the baffles on the subs with the Swope towers and center channel that I made previously. There's a few similar colors of dye involved in each finishing process which probably gets the credit for the easy blend.

                      I haven't been able to play anything on them yet, but I am very anxious to do so. I'm waiting on another speakon connector so I can make a DATS hookup for the sub. I want to run an impedance sweep with everything in the box to get a final tuning value and see where I ended up. Also, I still need to run that MiniDSP room correction to make this sound it's absolute best.

                      Honestly though, sitting on my couch looking at these things really made me a touch anxious (in a giddy good way). These things look like they're about to gang up on you and beat you with bass! I've never seen Interstellar before, but I hear there's some awesome LFE and low organ notes in that soundtrack to test them out. Otherwise, I'll be testing with some solid drums like Der Trommeler from Rush, The clear choice of In The Air Tonight from Phil Collins, and probably some Deadmau5 for the electronic bass side of things too.

                      As for the wife... she likes them too. She was initially shocked at the suggestion of two giant subwoofers in the living room, then she forgot about it, then remembered that I was making TWO subs sometime mid-project, but ultimately settled on "Man, those look GREAT!" As far as I'm concerned... mission accomplished!

                      Now to put velcro under almost everything in the house
                      Voxel Down Firing with Dayton SA70
                      Translam Subwoofers - The Jedi Mind Tricks

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