I have decided that i want to have a sub in my WRX wagon and keep it out of the way of the spare tire, but in order to get the sub to fit, and look clean i had to make the box larger than expected. The sub is a 12" Apline type X and the rec sealed volume is .9^3 but the range is upto 1.5^3

What will happen if this box turns out to be larger (i wont know untill i glass the back and do the math..) will i damage the sub? will it sound like ****?

Another thing i thought i could do is just put in a pice of 3/4" MDF to block off some of the air space (after i figure out how much is there)

Here is a pic of the box (before glassing)

 

Actually the box volume range for the SWR-1222D and 1224D is .7 -1.0 cuft, recommended sealed volume is .85 cuft, all the above are gross volumes.

Build the box, calculate volume and subtract extra volume by installing internal bracing, [ "use up" the extra volume], if the box is too big by 200 cuin, install 200 cuin of bracing. 94

 

ha ha i was hoping there might be a better option than that, im not looking to have a 200lb box lol. Is there any other material that i can use to take up the extra space?

 

You could use anything that takes up volume, styrofoam fiberglassed into place would work. 94

 

A easy way is to use packing peanuts to measure internal volume. It works for me when I do glass stuff. I know one installer that uses rice But if it works it works.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by fcm &raquo;</TD></TR><TR><TD CLASS="quote"> You could use anything that takes up volume, styrofoam fiberglassed into place would work. 94</TD></TR></TABLE> maybe on that note, some expanding foam like great stuff may work. just be careful, it expands alot.

 

I was thinking of cutting a pice of mdf, and blocking off a calculated section and than filling that section with expanding foam. That should work pretty well.

 

Anything that uses up volume will work, even just the expanding foam. 94

 

i figure its easier to keep the volume to spec with the wood there since you can than take into account the amount it is going to expand

 

I'm sure we're all taking the volume of the sub basket/magent into account as well. This might be a stupid assumption, but when manufacturers list box volume requirements, that is for box volume excluding the sub's volume; so you'd build the box xx amount more in volume to make up....someone correct me on this.

 

I would imagine under there "optimum box dimensions and volume" section that that is taking into consideration the driver displacement. I know on my Type x that is has optimum box dimension and they wouldnt give that to you if it wasnt taking the sub into account. Although this may be one of those things like RMS wattage, some manfatures follow the rules, some dont. I'm not fully sure.

 

Alpine gives you both gross, or "build to volume", [including subs volume] and net, [not including subs volume, and based on a 3/4" baffle]. 94

Info from... http://vault.alpine-usa.com/pr...D.PDF