View Full Version : Check My Box! Woulda never thought..

04-08-2005, 01:51 AM
Woulda never thought I would be one to do this. But here goes.

This will be a build-in for a single Avalanche 15. If all goes well with this one, I have every intention upon buying a second.

Not exactly a "check-my-tuning" thread either... just...

are there any MAJOR flaws in this design?

Supposedly about 4.1 cubes tuned to 26 hz. However I will be bracing, which will bring my box volume down, and my tuning up. Sub mounts on the 14" wide side, and the height is also 14" tall internally. All will be done with 3/4" MDF.

I'm mainly concerned that the lower left hand corner will do somethin' funky with the bass... and i mean somethin' bad...

The shape of the lower left corner is because I have plenty of space to use there.

Of course all port edges will be rounded.

Let me know what you think.



04-08-2005, 06:11 AM
Morning bump - someone push me in the right direction?

04-08-2005, 06:16 AM
SE still for sale?

04-08-2005, 06:27 AM
Yes. There is one potential buyer so if you are interested, he has a few more days until I'll put it back up for grabs.

Make an offer :)

and.... help me out on my box!

04-08-2005, 07:47 AM
bump for the box question :)

04-08-2005, 08:16 AM
I'll take a look at it when I get out of class today if somebody hasn't already.

04-08-2005, 08:26 AM
I think that if you rounded off that corner slightly and then tunded to 25 Hz, allowing for the displacement of your bracing and "rounded corner". In other words, rounding that corner will take away some Box volume, maybe .2 of a cube? However, I do not think that you would even audibly notice any difference if it was a rectangular box or a irregular shaped box such as yours. Do you think air will get trapped there?

Go to www.Bcae1.com (http://www.bcae1.com) and there is a calculator there (on the right side of the page scroll down until you reach the calculators, it is number 110, click on that and scroll almost all the way down, BINGO!) and in the calculators there is a bracing calculator.

04-08-2005, 10:33 AM
In other words, rounding that corner will take away some Box volume, maybe .2 of a cube?

What? more like .002ft^3

04-08-2005, 10:52 AM
The shape of the box doesn't really make too much of a difference. Your more worried about volume when porting a box.

If it was my box I would take a piece of wood about 4'' wide and however long you need it and make an angle on it so that it looks like this \__/ and make it angled enough so that it will fit in that angle in the corner. That wont allow air to get trapped there or it will atleast help it not get trapped there. As far as how much cuft~ you will lose. Idk...you estimate :P

But thats what I would do...if you dont understand I can draw it out for you :D

04-08-2005, 11:35 AM
dude. just get a 3" PVC pipe and stick it in the extreme left corner everyone is worried about, get a can of that "great stuff" expandable foam, and spray it behind the PVC pipe where the corner and the round edge of the PVC is.

when it dries, yank off the pvc pipe (make sure its wedged in place when its all drying) and sand it down a little.

no more corner, no more trapped waves, no more "so called" issuses.

but that box looks fine from what i can see. i wouldnt be too worried about it to be quite honest - it should work without any modifications as long as you calculated it right. how TALL (inner) is that box? ill check it out later tonight or tomrrow for ya.

04-08-2005, 11:50 AM
how TALL (inner) is that box? ill check it out later tonight or tomrrow for ya.

it's 14" tall... and i am SURE i did my calculations correctly. With no bracing that's tuned to a little above 26... then I'll add a few braces across the inside and hope to bring that tuning up a little bit. And I think when timb was talking about rounding that corner, he was thinking more of a 4 or 5" radius corner, to take out 0.2cuft :)

I think Seth has a good idea. And about the PVC idea, that's good. I think I'll go ahead and throw some 3" diameter PVC over near the port to ease air through there.

req, i'm sure you're dying of jealousy.

seriously... if you are interested let me know... i'm buying an avalanche 15 tonight right after i get home from school at 2:00pm... and it will have to be dual2ohm. when the time comes that ascendant offers a quad2ohm configuration, i am pretty sure i would be interested in selling you the avalanche at a decent price (i'll give it to you for like $75 less than retail) and then buy two quad2ohm configs.

let me know :)

04-08-2005, 11:57 AM



i NEEEED to get the car acutally DRIVING before i buy my sub :(

so ill just get my frontstage set up in the meantime and then get the sub installed.

gonna be mad temp in the trunk tho. but yea, maybe a verticle brace in the middle, and then one horizontal i suppose. although, with not over 1kw, it shouldnt flex THAT much. maybe just get some thin wood slats, and resin them to the inside walls of the box instead of a horizontal brace...

the coolest part about this kind of box is that you will have trunk space that dosnt have any speakers shwoing, and lots of amp rack room :)

i like it, but you are almost definatly going to have to seal the trunk from the cab around the edge of the boxes.

04-08-2005, 12:12 PM
I was planning on fiberglassing two layers or so from the edges of the baffle straight to the inside edges of the rear seat hole.

the hole is 13" tall with circles on the edges that have 15" radius, and at the widest point it is 35" wide.


Sadly, if I end up building two of the boxes shown in the first post, I will have no more than 2-4" around my box in any direction :)

ok maybe a little more than that in parts, but i don't know where.

i'm building an amprack onto the back of my fold-down seats, and the amprack, when the seats are folded up, neatly fits into the trunk opening :D

i'll keep my 15" long enough for me to tell you what i think of it, and when the quad4's come out i'l buy two, and sell you my dvc2 :D what do you think