JaredGMS

Ok guys, some input would be appreciated.

I used to work at a stereo shop, but we did very little truly custom work, and when we did, the owner did it himself (best custom enclosures I have EVER seen...)
Anyways, I have built boxes before, and plan on going to a sealed enclosure with my polkMOMO 12...but what is the best way to incorporate the box into a custom deal? I am not going to use any fiberglass, just 3/4" MDF and carpet...

The plan is to have the trunk open to look like a panel in the rear of the trunk, with the sub on one side, and a recessd panel for the amp on the other...My biggest question is whether I simply use an extended panel for the front of the box for the whole panel across the front facade, or do I build the box complete, and then attach another panel to the side to make the front face?

Also, what is the best way to secure the whole assembly to the rear of the space? I really don't want this thing sliding around when I gun it....

Any ideas and or improvements on the design are greatly appreciated!!

thanks

elduderino

Personally, I would make the box separate, and then make a "beauty board" that fit the trunk, mounted to the F of the box, framed the woofer, and had the amp mounted to it in some way. First, totally finsih the box, get it done, get it mounted, and THEN start making the beauty board template out of cardboard - otherwise you have issues with things lining up and moving around.

I would suggest at least using fiberglass in the following way: Use 3/4" for the front (the "baffle"), use 1/4" MDF for the rest of it, and then glass it from the inside before installing the woofer. Lighter, stronger, and the inside is no longer perfectly flat...

If you don't do that, I'd use 3/4" all the way around. I wouldn't worry about using 1" on the front because with the beauty board, you have no reason to router the baffle and flush-mount the woofer. You can just mount it from the front and have the entire 3/4" thickness.

I usually look for existing bolts (like for the optional cargo net?) on the floor of the trunk, and make brackets that mount the box to them.

JaredGMS

one more question....I am looking at making a sealed 0.9ft3 box...does the shape of the 0.9ft3 matter? Can I make a long rectangular cube instead of a square cube? How much back clearance does the box need from the magnet back?

Also, what do people think about reverse mounting of a sub (firing into box..)?

DRM600

the shape (square, rectangle, round, cylindrical, molded to some contours or whatever) of your enclosure doesn't matter as long as the volume is equal to what you want. from my experience, leave at least one inch of clearance from the back of the magnet.

elduderino

The only caveat I would add about shape is that if your front and rear walls are parallel, make the box as deep as possible. Non-parallel walls are best.

And firing into the box works fine for sub-bass with many woofers, but use a LOW xover point, and the midbass coming off of the back of the cone doesn't sound that good in my experience. Of course, in a trunk, shouldn't matter much. In hatches it was a different story at times...

DerrickM

I disagree--the internal dimensions should be calculated to minimize reflections. A cubic box is the worst design. (Even with polyfill, it's still a good idea to pay attention to this).

See the "golden ratio" section of this webpage:

http://www.mtxaudio.com/caraudio/edu...nstruction.cfm