So, i am HOPING this is the final box design for my SPL-15 as I am going ot buy some MDF here in a couple hours. HOWEVER i just thought since this is my very first box design done by myself I would throw it up here for you'all to check out and let me know what you think. Nothing Fancy, just a simple ported box....

Edited June 19, 200916 yr by k_schutte

i didn't run the numbers but a quick glance says it "looks" ok. I'd suggest at least some form of bracing considering how large the box is.

fixed....

Edited June 19, 200916 yr by k_schutte

definitely a slot port. I'll run all the numbers in a minute if someone doesn't beat me to it

needs the back, top and bottom plates braced (even a simple 2"x2" brace will help. with that large of a panel you'll have flex.

my general rule of thumb is if it's over 18" (long or wide) it needs a brace.

I didn't run the numbers but looks good.

I was planning on using some 1-1/4" dowel... one left/right and one up/down, would that work good enough?

I have my old box and stuff laying around and considered "window bracing" but I am trying to keep the box volume as high as possible!

window bracing would be better than dowels. And with a box that large, i'd gladly sacrifice a little volume for proper bracing, it'll help more than the volume it displaces.

2x4 would work fine, dowels can work but i usually have 2x4s laying around so that's what gets used (way too lazy to cut out window bracing)

Leaving right now... I will probably see what they have up there and then decide what ot do for bracing. I was thinking threaded rod might be a good choice too... I guess we will see what i come up with. Wish me luck!

"window" bracing is easier/cheaper than threaded rod... the dowels will help... better than nothing (as long as you can get them secured w/out cracking the wood) also more expensive than the 2x4 route.

Ended up getting some 2"X2"x8' for like $1.48~ so i went that route. Don't have a nail gun anymore so i just got some "self pre-drilling" screws and liquid nails. It's over 90* outside so i just had Home Depot cut it all for me (except the circle) and I am going ot throw it together in my "office" where it is nice and air conditioned! I am literaly sweating from just walking to my house form my car 3 times (its about 10ft)

ANYWAYS... forgot to get paint for teh port so i guess I am just going to skip that part, probably won't carpet teh box anyways for a little while so it isn't really a big deal. I am just ready for some damn bass back in my car!!

what about double baffle?

if the port is 6" wide there's no reason you can't paint it now. it's a small step but really helps hide a lot of crap. I highly suggest eventually carpeting, if only for the experience

btw for future reference, drywall screws, predrill and use a good quality wood glue like tite bond.

btw for future reference, drywall screws, predrill and use a good quality wood glue like tite bond.

X2

tite bond works much better than liquid nails, it absorbs into the wood making it "one-piece" the liquid nails is flexible and not really a good choice.

(several people use liquid nails, however, I cannot suggest using it.)

HHHMMM.... question i guess i should have asked before...

As for carpeting, I have done it several times, which is how i know i don't like doing it ;-)

I am going to have ot rebuild a box later on when i have more time, I should have known better than to listen to the guy at Home Depot. Plus he plain sucks at cutting!! I usualy just have saw horses, a circular saw, square and tape measure and my cuts where way better than what he did on that "stand up table saw" some are up to 1/8" +/- the measurements i told him. I even took time to draw it all out TO SCALE on a piece of graph paper so he knew exactly what cuts to make and everything. I think he just didn't take the width of the blade into account when he made the cuts.

Plus these screws SUCK and are splitting the wood on the corners/ends and when the head hits, instead of sinking in AT ALL, they just spin like hell. He also told me Liquid Nails was a better adhesive then the Tight Bond (which is what i actualy had ot begin with) I am going to have to carpet this box now just to make it presentable. I usualy use an air powered nail gun and Tight Bond but thought this way would actualy be better man was I WRONG!

Oh well, I am going to finish it up and fix it up the best i can for now and get it metered tomorow. Then i will rebuild the box at a later date and see if it might change anythign at all...

only thing is I would use wood screws not dry wall screws they hold better

but that may just be for birch I won't use mdf

My old box for my 15" Icon is smaller than that and I thought I didnt need any bracing at all. My box flexed so much and the woofer just broke the box down and tore it up.

only thing is I would use wood screws not dry wall screws they hold better

but that may just be for birch I won't use mdf

Wood screws and drywall screws have the same thread pitch, aside from fine thread drywall screws which are actually better as there is more surface area.

they may have the same pitch but the wood screws stick out more into the wood I've blown plenty of boxes apart so I have gotten to test out a bunch of screws

What do you mean, "they stick out more?"

So... This was just plain a DISASTER!!! the box turned out like shit! Honestly it is probably worse than the first box i ever built back when i was 15 with partical board and brad nails. Stuff split everywhere, the side of the box the port is on was cut 1" short and in my rage i forgot to put the bracing in. All in all I pretty much wasted $50~ on this box and will probably just put the sub in my old box if it would be OK...

the other box i have is 4ft^3 and tuned to 33hz, double baffle, flush mount, braced and doesn't look near as bad. Only thing that worries me is I am looking for SPL and I don't think that other box being as small and low tuned would give the the desired results! I wish I could find someone local that would build boxes for a decent price... Or atleast someone that knew how to fuckign cut the wood RIGHT so the shit would actualy look decent and more importantly FIT decent.

ANYWAYS, I am going to toss it all in there and see what happens...

Well, I am happy(ish). Finaly got the sound of my HDC315 back except a little harder IMO... I assume the sound deadening has a lot to do with the lack of flex now still moves a decent amount but nothing like before...

Should be a BEAST when I get my new box and port the rear deck. Once i get the new box I am going to crank teh power up a little more too, Gain is only about 1/3 right now... don't have a DMM anymore to set it so i figure I will leave it for now. HOWEVER if it is that good right now when i get the new box and turn the power up... I CAN"T WAIT!!!

Now i just have to figure out what to do with my rear suspension... Thinking I will airbag the whole car this winter but i don't want to keep scraping/slamming all summer long with all that weight back there....

Edited June 20, 200916 yr by k_schutte