And... We're Off! Dual 18" Sealed Sub Build

scubalab
scubalab Posts: 3,101
edited March 2017 in DIY, Mods & Tweaks
Well, I've been sitting on the Ultimax drivers since last Thanksgiving and the Crown amp since Last Spring. Finally ordered some additional parts from Parts Express, picked up over 400 lbs of mdf (2 sheets 3/4" and 2 sheets 1/2"), glue, screws, dowel rods (for internal bracing) primer and paint. Measurements nave been taken, dimensions calculated, cut patterns laid out, and saw ready to make the first cuts.

The end result will be two subs in 20" wide x 34" tall x 22" deep sealed boxes. Top, bottom, back and sides will be 1-1/4" mdf, front baffle will be 2" mdf. It'll basically be a box in a box. I'll build the inner box with 3/4" mdf. All joints glued AND screwed. Front baffle will be 1-1/2". Then I'm gluing 1/2" mdf around all sides, no screws, sanded flush on all joints, 1/4-round routed corners, primed and painted satin black (I FOUND SOME BLACK PAINT! Well it's technically not black... sorry). Plan to brace it internally with 3/4" dowel rods recessed and screwed to the sides.

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Post edited by [Deleted User] on
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Comments

  • EndersShadow
    EndersShadow Posts: 17,517
    Finally, slacker!
    "....not everything that can be counted counts, and not everything that counts can be counted." William Bruce Cameron, Informal Sociology: A Casual Introduction to Sociological Thinking (1963)
  • scubalab
    scubalab Posts: 3,101
  • scubalab
    scubalab Posts: 3,101
    Sides for inner boxes are cut!

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  • Conradicles
    Conradicles Posts: 6,010
    Very nice. I love my 18" passive sub.
  • scubalab
    scubalab Posts: 3,101
    Calling if for the day. Big holes cut. They all line up great. Just hope the driver fits! :o

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  • Thorton
    Thorton Posts: 1,324
    Very nice. Are those Prototypes for me? lol.

    Keep us posted on the progression.
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  • VR3
    VR3 Posts: 27,965
    Very interested in your final product... expected F3??
    - Not Tom ::::::: Any system can play Diana Krall. Only the best can play Limp Bizkit.
  • EndersShadow
    EndersShadow Posts: 17,517
    Give me a bit and I will get it for you. My wife is using my laptop so I can't pull up the WinISD simulation.

    But it's around a 6 cubic foot box IIRC and a Dayton Ultimax 18" driver with 775 watts per driver.... until I convince him to double up the amps and bridge them to give each driver 2500 watts lol...
    "....not everything that can be counted counts, and not everything that counts can be counted." William Bruce Cameron, Informal Sociology: A Casual Introduction to Sociological Thinking (1963)
  • EndersShadow
    EndersShadow Posts: 17,517
    edited March 2017
    @VR3

    Looks to be about 30hz if my WinISD graphs are right assuming its a ~6 cubic foot box....
    "....not everything that can be counted counts, and not everything that counts can be counted." William Bruce Cameron, Informal Sociology: A Casual Introduction to Sociological Thinking (1963)
  • VR3
    VR3 Posts: 27,965
    shooting for music or HT first?
    - Not Tom ::::::: Any system can play Diana Krall. Only the best can play Limp Bizkit.
  • scubalab
    scubalab Posts: 3,101
    edited March 2017
    Mostly (90%+) HT. Very little music on that system.
  • EndersShadow
    EndersShadow Posts: 17,517
    edited March 2017
    @VR3

    He decided on sealed due to the easy of building, the lack of a need for a highpass filter to protect the driver, and its a ton easier to simulate in winisd lol.

    Given his room is fairly closed off he should get some decent room gain and his chairs are on risers so I'm hoping all that works in our favor.

    Ideally large ported boxes would be best, however the other criteria dictated we go sealed.

    I'm very hopefully he will be satisfied. If not I'm gonna have some egg on my face since I pushed him in this direction :blush:
    "....not everything that can be counted counts, and not everything that counts can be counted." William Bruce Cameron, Informal Sociology: A Casual Introduction to Sociological Thinking (1963)
  • scubalab
    scubalab Posts: 3,101
    Yep. I blame Dan if this fails!

    In all seriousness, it doesn't take much to make me happy. I'm running an SVS cylinder sub now that I'm happy with. I can't imagine these won't top my current sub. My main goal was to build something concealed in the wall and I fortunately had the room for two!
  • Face
    Face Posts: 14,340
    Nice, I run a very similar setup in my HT. 2 UM18s, both in 7cf enclosures and each powered by a bridged Crown XTi2002. They are used as end tables, so there's no lack of bottom end. My favorite demo piece is the into of Edge of Tomorrow, where is drops down to 10hz..just be careful on the volume. My only recommendation to you is, consider a second amp. ;)
    "He who fights with monsters should look to it that he himself does not become a monster. And when you gaze long into an abyss the abyss also gazes into you." Friedrich Nietzsche
  • Face
    Face Posts: 14,340
    One more thing, consider Dutatex instead of spray paint. It's easy to use, there are no fumes, and it dries quickly, slowly becoming rock hard after a week. The nap of the roller will dictate the texture of the finish. I used a 14" wide, 3/8 nap roller from Lowes for a slightly raised texture and no lines between applications.
    "He who fights with monsters should look to it that he himself does not become a monster. And when you gaze long into an abyss the abyss also gazes into you." Friedrich Nietzsche
  • scubalab
    scubalab Posts: 3,101
    Thanks for sharing that Face. Someday, I'll likely upgrade to two separate amps (one for each sub), but for now, I think the 2500 should be able to drive the two 18's fairly well. My boxes are going to be a bit smaller at about 6 CF (probably a little more like 5.5 CF taking into consideration the bracing and the drivers.

    I'm hoping to make a little progress on these this weekend. I'll update the thread with pics! My goal is to complete the build of the boxes, and with all the parts for the interior (3/4") boxes cut, I just need to assemble and build in the bracing. Ideally, I'm hoping to then get the 1/2" cut for the outer boxes. If all goes well, I'll get all the 1/2" sides glued over the 3/4", and it'll be ready to hit the corners with the router and ready for paint next week.

    Parts for the cables (from Parts Express and Douglas Connection) have been delivered and are waiting for me at home. I also have some T Nuts from Stafast.com that should be delivered today. I've got no excuse to not finish these now.

    Getting closer!
  • Conradicles
    Conradicles Posts: 6,010
    Face wrote: »
    One more thing, consider Dutatex instead of spray paint. It's easy to use, there are no fumes, and it dries quickly, slowly becoming rock hard after a week. The nap of the roller will dictate the texture of the finish. I used a 14" wide, 3/8 nap roller from Lowes for a slightly raised texture and no lines between applications.

    I used this and love the results. Nice recommendation Face.
  • EndersShadow
    EndersShadow Posts: 17,517
    Face wrote: »
    Nice, I run a very similar setup in my HT. 2 UM18s, both in 7cf enclosures and each powered by a bridged Crown XTi2002. They are used as end tables, so there's no lack of bottom end. My favorite demo piece is the into of Edge of Tomorrow, where is drops down to 10hz..just be careful on the volume. My only recommendation to you is, consider a second amp. ;)

    Hehehe.... I may have also been telling him that too... mainly because I want to have him ripple the carpet on his basement slab with the bass hehehe.....

    Also nice to see you posting @Face
    "....not everything that can be counted counts, and not everything that counts can be counted." William Bruce Cameron, Informal Sociology: A Casual Introduction to Sociological Thinking (1963)
  • scubalab
    scubalab Posts: 3,101
    I considered the DuraTex, but went with spray paint because of the cost difference. I figure if I'm not happy with the paint, I can always go over it with DuraTex, but it'd be much harder to go the other way around. Is there any difference between DuraTex and the roll on bedliner paint?
  • scubalab
    scubalab Posts: 3,101
    I've got some work ahead of me. This was waiting for me when I got home this afternoon after being out of town teaching since Tuesday evening...

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  • scubalab
    scubalab Posts: 3,101
    One box (inner) just about done...

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    Front baffle dry fit and without front-to-back bracing...

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  • EndersShadow
    EndersShadow Posts: 17,517
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    "....not everything that can be counted counts, and not everything that counts can be counted." William Bruce Cameron, Informal Sociology: A Casual Introduction to Sociological Thinking (1963)
  • EndersShadow
    EndersShadow Posts: 17,517
    edited March 2017
    I don't see no zip ties around those dowel braces....

    And I wanna see pics of how crazy you went with scre-wing it together lol...

    *apparently screw-ing" is censored
    "....not everything that can be counted counts, and not everything that counts can be counted." William Bruce Cameron, Informal Sociology: A Casual Introduction to Sociological Thinking (1963)
  • scubalab
    scubalab Posts: 3,101
    Just for you Dan...

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  • mikeyb128
    mikeyb128 Posts: 2,885
    ^^^ I hope you cut the excess tie straps off! I see people leave them all the time in automotive and it drives me nuts!
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  • scubalab
    scubalab Posts: 3,101
    I will definitely cut them off! My OCD would not allow me to leave those ends in there! It would drive me nuts too. :)
  • EndersShadow
    EndersShadow Posts: 17,517
    edited March 2017
    mikeyb128 wrote: »
    ^^^ I hope you cut the excess tie straps off! I see people leave them all the time in automotive and it drives me nuts!

    Beat me to it! Although my OCD would lead me to do it on both sides so its an X lol.....

    And then maybe throw a brad nail or two in there or maybe a screw just because......
    "....not everything that can be counted counts, and not everything that counts can be counted." William Bruce Cameron, Informal Sociology: A Casual Introduction to Sociological Thinking (1963)
  • msg
    msg Posts: 9,308
    Lots of good OCD here. Mine would dictate that the zip ties at the very least all be installed in the same orientation, or at least mirrored left/right. And snipped, of course.

    Are the dowels friction/compression placed, or will they see glue as well, hot or otherwise?

    Looks like a fun project. Sub'd. (ha. subscribed)
    I disabled signatures.
  • msg
    msg Posts: 9,308
    PS
    Not having any experience with sub or speaker building, are zip ties enough to prevent vibration of the dowels against each other, or would it be wise to place some little sorbothane pads between before zip tying? My luck would dictate that I'd be pulling the baffle off 5 minutes after firing up, to address buzzing rods.
    I disabled signatures.
  • scubalab
    scubalab Posts: 3,101
    msg wrote: »
    Lots of good OCD here. Mine would dictate that the zip ties at the very least all be installed in the same orientation, or at least mirrored left/right. And snipped, of course.

    Are the dowels friction/compression placed, or will they see glue as well, hot or otherwise?

    Looks like a fun project. Sub'd. (ha. subscribed)

    LOL. It's funny how OCD differs in people Scott. Mine? I actually installed the zip ties in the same direction, but mirrored around the vertical centerline of the sub. And they will be snipped. I literally threw those on the dowels late last night just to shut Dan up, :p and it was too damn cold to run out to the garage to get the snips!

    Great idea on putting something in between where they touch to keep them from rattling! I'll cut a little piece of the speaker gasket tape and wedge it in there. I'll also probably put another zip tie on each cross like Dan mentioned. Everything is very tight. The dowels are recessed in a 1/4" deep routed hole, glued, and screwed from the outside of the side walls. I should have taken pics of that along the way!