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View Full Version : Box build, am I calculating this correctly?



Alter Ego Trip
07-31-2009, 03:14 PM
I'm working on stuffing some 12" SE's under the back seat of my truck. I'm trying to keep it as utilitarian as possible without drawing any needless attention. I'm raising the seat 1-1/4", as this is the minimum clearance I can get away with to fit the sub, after the box enclosure design. I'm using the subwoofer enclosure calculator off 12 volt. I'll try to explain this the best I can. The back wall of the enclosure (height 2), will be at a 50 degree angle to parallel the floor curve in my truck. Based on this I'm trying to figure out my approximate box volume. The bottom figures show a normal box with a cf calc of 1.02. I then input the values into the above calc to figure out the extra cubes from the 50 deg back slope. If you measure the bottom of the box and the top of the box, the 50 degree angle pushes the top out 3" further than the bottom. So based on this I get a volume of .138. I then subract the sub's displacement of .16 (I guessed a little as SE shows .15 but seeing as my sub's will be mounted from the bottom instead of the top I added a tad). So if my screwy math is correct, I should have a net sub volume of 1.0, exactly what SE recommends. For those that followed my rambling, does this look right to you?

Also, when calculating the recommended sealed enclosure on win, it states ideal is 1.63. Why the difference from RE which recommends 1.0 as ideal. I figure RE would have the best recommendations.
http://pic50.picturetrail.com/VOL426/2023328/8345252/370800528.jpg

altoncustomtech
07-31-2009, 05:02 PM
That may be correct, however you need to also give room for the displacement of the subwoofer..... For example, if the sub's displacement is .2 cuft.... then your enclosure will have to be 1.2cuft to have the correct size for the sub.......

Alter Ego Trip
07-31-2009, 05:11 PM
That may be correct, however you need to also give room for the displacement of the subwoofer..... For example, if the sub's displacement is .2 cuft.... then your enclosure will have to be 1.2cuft to have the correct size for the sub.......

I did, read about the middle of my ramblings. :) RE spec's .15 and I added .01 seeing as it will be mounted from underneath.