Beginner looking to build

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Hello,
I'm pretty much a beginner in the whole DIY enclosures and subs thing, so i apologize for being the stupid annoying noob ;)
Anyways, for my project, i'm looking for decent frequency response, reasonable SPL (though the occasional showing-off volumes can be fun :p ) and, most importantly, something affordable. The sub will typically be in a small room (my present dorm room is... well, its about the size of a dorm room. go figure.) and i've been looking around online at various driver options in the ~100 dollar price range, such as Dayton's 12" RSHF (or something completely different).
driver size (or number of drivers...) isn't really a huge concern, as long as the enclosure isn't too ludicrously large.
Also, I'm debating between a sealed enclosure (easier to build for me and smaller) versus a vented enclosure. From what i've graphed in winISD, it looks like a vented would always be the way to go, but then i heard about room gain. what exactly is room gain and how should i factor it in?
 
alrighty, now that i've spent a fair bit of time de-noobifying myself, i've begun to evaluate my build.
Driver: Dayton RSHF 12" ( http://www.partsexpress.com/pe/pshowdetl.cfm?&Partnumber=295-464&scqty=1 )
Amp: Dayton 240w plate amp ( http://www.partsexpress.com/pe/pshowdetl.cfm?&Partnumber=300-804&scqty=1 )
Box:
This is where i'm still hung up. i'm shooting for an internal volume in the 60-ish liter range, as that range gives a fairly flat curve in a sealed box with room gain estimated for my room ( -3 dB at 13.3 hz with a <1 dB peak around 30hz. I'm using a linkwitz transform to approximate room gain, where f0 = speed of sound/2*longest dimension of my room, which yields around 40hz, fp = 15hz, and q = .707. i got these numbers/idea from a thread on the winISD forums). I'm planning on using a sealed enclosure made of MDF, assembled from 6 1.5 foot square pieces of 3/4" MDF, with a 3-inch high brace perpendicular beneath the driver (or perhaps a different height that would physically support the driver? not sure about this bit.) works out to 95 liters externally, and internally approximately 70 liters before taking the driver and plate amp into account.
I'm not really sure what else i need/am missing at this point. I've also got some speaker sealing caulk and driver mounting kit in my parts express shopping cart, and wood glue and wood screws are in abundance.
One more thing: any tips on cutting clean holes for drivers?

So, in short: good idea, bad idea? good parts/well matched? good box plan?

I know this isn't a particularly advanced or innovative project, but we've all got to start somewhere...
 

GM

Member
Joined 2003
Looks like you got it covered, though it's a good idea to mass load (brace) the driver from the back wall and if you ever buy another plate amp, get one with a variable phase adjustment.

Folks usually lightly stuff the cab with polyfil too.

Most folks either use a jig saw or a plunge router with a circle jig such as the Jasper or you can make your own: http://www.partsexpress.com/webpage.cfm?&WebPage_ID=3
http://www.speakerplans.com/index.php?id=guide2

Yeah, you were smart, I was dumb enough to use a Pantograph to scale a pic in a mag of one of these to build a ~1/4 scale version: http://www.lansingheritage.org/images/altec/specs/pro-systems/lf-horns/page1.jpg
 
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