And... We're Off! Dual 18" Sealed Sub Build
scubalab
Posts: 2,983
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.
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.
Post edited by KennethSwauger on
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Keep us posted on the progression.
Ethernet Filter: GigaFOILv4 with Keces P3 LPS
Source: Roon via ethernet to DAC interface
DAC: Bricasti M1SE
Pre/Pro: Marantz AV8805
Tube Preamp Buffer: Tortuga TPB.V1
Amp1: Nord One NC1200DM Signature, Amp2: W4S MC-5, AMP3: W4S MMC-7
Front: Salk SoundScape 8's, Center: Salk SoundScape C7
Surround: Polk FXIA6, Surround Back: Polk RTIA9, Atmos: Polk 70-RT
Subs: 2 - Rythmik F25's
IC & Speaker Cables: Acoustic Zen, Wireworld, Signal Cable
Power Cables: Acoustic Zen, Wireworld, PS Audio
Room Treatments: GIK Acoustics
"No, that's silly talk. Dude, you can't possibly be this audio dumb so quit the act." - Doro
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...
Looks to be about 30hz if my WinISD graphs are right assuming its a ~6 cubic foot box....
"No, that's silly talk. Dude, you can't possibly be this audio dumb so quit the act." - Doro
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
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!
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!
I used this and love the results. Nice recommendation Face.
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
Front baffle dry fit and without front-to-back bracing...
And I wanna see pics of how crazy you went with scre-wing it together lol...
*apparently screw-ing" is censored
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Theater:
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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......
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)
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.
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,
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!