Announcement

Collapse
No announcement yet.

Shockwave Build Thread

Collapse
X
  • Filter
  • Time
  • Show
Clear All
new posts

  • Shockwave Build Thread



    ( ( ( ( s h o c k w a v e ) ) ) )
    ____________________________________________

    objectives
    inexpensive 3-way with a coaxial driver and 7" woofer
    meant for desktop nearfield listening
    aiming for f10 of 35Hz
    very close to sealed, overdamped impulse response
    group delay x frequency under 400 rule being followed
    mdf - silicone - tile constrained layer sides, top and bottom
    linear phase crossover
    ____________________________________________

    drivers
    rockford fosgate r1675x2 6.75" coaxial driver




    vifa/tymphany pl18wo-09-08 woofer


    parts express #299-018 buyout passive radiator



    ____________________________________________

    plan of attack
    concept
    design
    c.a.d.
    sawdust
    glue
    cut holes
    finishing touches
    measurements
    crossover design
    buttoning up
    finished

    ____________________________________________

    concept
    so i've been helping out my parents build a house lately mainly because they're letting me live in it rent free while i'm in school. new room for grey means new battlestation since i'm a total computer gaming nerd. one thing i've never had is some really nice looking speakers on my desk and i need to remedy that.

    i bought the vifa woofers from mr. scott quick a while back and needed to put them to purpose. i really love the aesthetic of coaxial drivers, having two in one really cleans up the baffle and allows for a more compact design, which is great because i over-engineer everything and like to try new concepts for each build.

    a few months ago i stumbled upon this rockford fosgate driver while looking at car audio stuff. wow, they're only $40 on amazon prime and would you know it, i got a $25 gift card from the parents for xmas.

    modeling the woofer hundreds of times and slowly working out a shape and various alignments. sealed is great quality bass, but i've done 3-4 builds now with sealed. ported is too "floppy" - if i may - and balancing the port volume and enclosure volume is tricky, not to mention i need a 2.5" port in a .5cf box which is silly huge, and in turn, ventures into peter north territory.

    so i opened up parts express' website and looked for a passive radiator, size doesn't change, so it's more simple than a port. first one i picked, i get a similar response to sealed, but with more booty, and my anaconda don't, so that was the way to go. group delay, what's that? did a little research, and read about the 400 rule (frequency x delay in ms <= 400) and tweaked my box size a little to attain that quality. gotcha. unibox (sorry bagby, i just prefer unibox still) says the impulse response is nearly identical to the sealed, over-damped impulse response, which i used in my last build and i loved those speakers, didn't want to give them away, but they're being enjoyed by a real vinyl lover, my bff.

    so the new things i'm trying out this build are: coaxial driver, passive radiator, constrained layer, (possibly) hardwood baffle, and distortion measurements. This will also be my second ever passive crossover.

    finally the name, in case you were wondering is my favorite transformer, he's only got one eye (coax driver looks like an eye).










    ____________________________________________

    design
    with this being a desktop speaker, they need to be compact, but not too compact because i have a pair of 27" monitors that i use.

    after tweaking the design a bit i experimented with a piece of birch, silicone and tile, to see if it compresses and after a couple weeks, it's still sitting pretty at 29mm thick. 19mm for the wood, 3mm of silicone and 7mm thick ceramic tile. so i fired up boxycad and 1.1412" thick top, bottom, and sides. the front and rear baffles are different monsters, they'll be 1.5" thick on the backside, and a total of 2.25" on the front with a normal 3/4" baffle and recessed drivers and a "facade" 1.5" thick with some fancy (to me) router work.

    the mid/tweet coaxial driver will have it's own compartment, which i sized to make the woofer compartment the correct volume. which leaves a small amount of room for the crossover between the woofer and passive radiator, or in the tiny compartment in the back of the box.


    ____________________________________________

    c.a.d.
    i have been using eMachineShop forever now, so that's what i use to draw stuff up and do simple 3D like the baffle, etc. the massive 1.5" roundovers and 1.375" chamfers are only meant to be aesthetic, but will probably just introduce some wiggles into the frequency response due to their size, no doubt. here's what i've got so far:





    this is as far as i have gotten, and i'm hoping to be able to cut some wood tomorrow, stay tuned for updates!
    Last edited by greywarden; 06-25-2016, 06:27 AM.

    रेतुर्न तो थे स्रोत
    return to the source
    leviathan system thread
    deadhorse thread
    shockwave build thread

    instagram :: greywarden_13

    in war, victory . . . in peace, vigilance . . . in death, sacrifice.

  • #2
    Re: Shockwave Build Thread

    love it !
    Paper Towers
    RS180P/28F surrounds
    Boombox

    Comment


    • #3
      Re: Shockwave Build Thread

      Thanks, you have no idea how long that took to put together, lol, that being said, I'll attempt to stick to the same format for future official updates.

      रेतुर्न तो थे स्रोत
      return to the source
      leviathan system thread
      deadhorse thread
      shockwave build thread

      instagram :: greywarden_13

      in war, victory . . . in peace, vigilance . . . in death, sacrifice.

      Comment


      • #4
        Re: Shockwave Build Thread

        Fun 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


        • #5
          Re: Shockwave Build Thread

          Nicely documented so far! Are you going to do anything custom to that coax driver?

          I like the idea of a coax point source, and looked at some drives. The car stuff with preset crossover limits tweaking options, unless you can get frd/zma measurements yourself, get to the individual inputs, and design an improved crossover.
          Electronics engineer, woofer enthusiast, and musician.
          Wogg Music

          Comment


          • #6
            Re: Shockwave Build Thread

            Originally posted by greywarden View Post
            Thanks, you have no idea how long that took to put together, lol,
            Hopefully faster than a "deadhorse" lol

            Comment


            • #7
              Re: Shockwave Build Thread

              Originally posted by wogg View Post
              Nicely documented so far! Are you going to do anything custom to that coax driver?

              I like the idea of a coax point source, and looked at some drives. The car stuff with preset crossover limits tweaking options, unless you can get frd/zma measurements yourself, get to the individual inputs, and design an improved crossover.
              Yeah I have measurement equipment. I plan to measure on/off axis response and distortion as well. I'll remove the cap on the tweeter and separate the two drivers so I can do up a crossover for them.

              Originally posted by killa View Post
              Hopefully faster than a "deadhorse" lol
              Man that was years ago, still catching crap for it haha.

              रेतुर्न तो थे स्रोत
              return to the source
              leviathan system thread
              deadhorse thread
              shockwave build thread

              instagram :: greywarden_13

              in war, victory . . . in peace, vigilance . . . in death, sacrifice.

              Comment


              • #8
                Re: Shockwave Build Thread

                ambitious!
                Seems like of lot of stuff into a pretty small box.
                Large roundovers should only help to smooth HF responses.

                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

                Comment


                • #9
                  Re: Shockwave Build Thread

                  Originally posted by donradick View Post
                  ambitious!
                  Seems like of lot of stuff into a pretty small box.
                  Large roundovers should only help to smooth HF responses.
                  Yeah it is rather ambitious, I'm not sure the roundover will affect the FR much with the giant chamfers, but I honestly have no idea. Guess I could do flat baffle measurements and compare them.

                  Also, we finally got power hooked up to the house today, so I'll be burning some midnight oil (not that I don't go to bed around 3-4am anyway)

                  रेतुर्न तो थे स्रोत
                  return to the source
                  leviathan system thread
                  deadhorse thread
                  shockwave build thread

                  instagram :: greywarden_13

                  in war, victory . . . in peace, vigilance . . . in death, sacrifice.

                  Comment


                  • #10
                    Re: Shockwave Build Thread

                    Cool project. Nice documentation. Do / will you have frequency response plots of the coax?

                    but, the resolution of your first photo and unibox graphs aren't playing nicely with the width of my browser window. you might consider resizing to prevent side scrolling.
                    - Ryan

                    CJD Ochocinco ND140/BC25SC06 MTM & TM
                    CJD Khanspires - A Dayton RS28/RS150/RS225 WMTMW
                    CJD Khancenter - A Dayton RS28/RS150/RS180 WTMW Center
                    CJD In-Khan-Neatos - A Dayton RS180/RS150/RS28 In/On Wall MTW

                    Comment


                    • #11
                      Re: Shockwave Build Thread

                      Originally posted by ---k--- View Post
                      Cool project. Nice documentation. Do / will you have frequency response plots of the coax?

                      but, the resolution of your first photo and unibox graphs aren't playing nicely with the width of my browser window. you might consider resizing to prevent side scrolling.
                      I'm going to make measurements, afaik there isn't a single car audio driver measurement anywhere on the web bc it doesn't matter when you put it in a car, it's gonna sound like junk, lol.

                      What resolution are you using? I have a 2560x1440 for my main, and of course it looks normal there, but I have a 1920x1080 in portrait, so only 1080 pixels wide and only the widest pictures are causing the browser to side-scroll, and only by like 20-30 pixels.

                      रेतुर्न तो थे स्रोत
                      return to the source
                      leviathan system thread
                      deadhorse thread
                      shockwave build thread

                      instagram :: greywarden_13

                      in war, victory . . . in peace, vigilance . . . in death, sacrifice.

                      Comment


                      • #12
                        Re: Shockwave Build Thread

                        small update
                        i didn't get any wood cut today (we got the electricity turned on and internet at the house, so i ended up listening to the 7.1 system i for a couple hours) but i did secure some scraps of the absolutely gorgeous ambrosia maple we used for the island countertop! i'll definitely add a couple pictures of the finished wood tomorrow because i'm super proud of my handiwork.

                        रेतुर्न तो थे स्रोत
                        return to the source
                        leviathan system thread
                        deadhorse thread
                        shockwave build thread

                        instagram :: greywarden_13

                        in war, victory . . . in peace, vigilance . . . in death, sacrifice.

                        Comment


                        • #13
                          Re: Shockwave Build Thread

                          Looking forward to the measurements. Like you said, I've never seen a measurement of a Rockford Fosgate or any other car woofer. Should be interesting.

                          Thanks for resizing. They look fine on my laptop now. I usually run chrome in a medium size window, even on a big monitor just to get it down to a normal size piece of paper. I find it easier... maybe I'm weird. But I appreciate it.
                          - Ryan

                          CJD Ochocinco ND140/BC25SC06 MTM & TM
                          CJD Khanspires - A Dayton RS28/RS150/RS225 WMTMW
                          CJD Khancenter - A Dayton RS28/RS150/RS180 WTMW Center
                          CJD In-Khan-Neatos - A Dayton RS180/RS150/RS28 In/On Wall MTW

                          Comment


                          • #14
                            Re: Shockwave Build Thread

                            Watching with much interest. I've mulled over using a car coaxial in such a manner, but am a little inexperienced yet at this hobby. I like that it allows a little downsizing (depending on woofer needs of course) of the enclosure. It also does away with any center-to-center spacing issues of side by side drivers.
                            Will the RF be in its own sealed enclosure, sort of a home grown sealed back mid, to prevent interaction with the woofer movements?

                            Comment


                            • #15
                              Re: Shockwave Build Thread

                              Originally posted by ---k--- View Post
                              Looking forward to the measurements. Like you said, I've never seen a measurement of a Rockford Fosgate or any other car woofer. Should be interesting.

                              Thanks for resizing. They look fine on my laptop now. I usually run chrome in a medium size window, even on a big monitor just to get it down to a normal size piece of paper. I find it easier... maybe I'm weird. But I appreciate it.
                              Well I didn't do anything, so..... idk what to tell you haha.

                              Originally posted by biscuitbarrell View Post
                              Watching with much interest. I've mulled over using a car coaxial in such a manner, but am a little inexperienced yet at this hobby. I like that it allows a little downsizing (depending on woofer needs of course) of the enclosure. It also does away with any center-to-center spacing issues of side by side drivers.
                              Will the RF be in its own sealed enclosure, sort of a home grown sealed back mid, to prevent interaction with the woofer movements?
                              Yeah it'll be sealed away in the 0.16cf compartment. Won't matter much when it's crossed to the woofer.

                              रेतुर्न तो थे स्रोत
                              return to the source
                              leviathan system thread
                              deadhorse thread
                              shockwave build thread

                              instagram :: greywarden_13

                              in war, victory . . . in peace, vigilance . . . in death, sacrifice.

                              Comment

                              Working...
                              X