Sub Box Plans for Dummies

car subwoofer box

Although it might seem to the uninitiated that certain freelancers for the former eHow.com had expertise to share on certain subjects – at least based on the number of posts they pounded out on related topics – the sad truth is that any expertise is merely a result of grabbing a number of similar "titles" and rewriting the same misinformation several times. A case in point is history major Nichole Liandi, who posted multiple articles about audio for "boom box cars," including the ItStillRuns post "How to Build a 12 inch Subwoofer Box."

Liandi cited, as always, something called the Car Stereo Cookbook (a volume we rather doubt was on her bookshelf). In other words, she likely got all her information from her other reference, a post that you can still find at Crutchfield. Sadly, she didn't read all the way through it, or she might have done a better job. Interestingly enough, the plans at Crutchfield were also written by a J-school grad – but at least they appear to have been vetted by a professional.

Nichole opened by telling her readers the "Things You'll Need." number one on that list is, believe it or not,

"Two 4 by 8 foot 3/4-inch MDF (medium density fiberboard) boards"

No one here would call a sheet of MDF a "board," but the real question is why you need two sheets. We wonder that because the first three steps are,

1. Cut two MDF panels measuring 18 by 18 inches with a circular saw or table saw. These will be the front and rear panels of the subwoofer box.
2. Cut two MDF panels measuring 18 by 12 inches with a circular saw or table saw. These will be the side panels of the subwoofer box.
3. Cut two MDF panels measuring 16 1/2 by 12 inches with a circular saw or table saw. These will be the top and bottom panels of the subwoofer box.

Why Liandi thinks you need two sheets of MDF for those cuts is beyond us. Our staff carpenter thinks you can cut them out of a half sheet (the total is 36" by 42" plus waste for the saw kerfs).

Nichole's unfamiliarity with constructing something out of MDF shows pretty clearly; as does her apparent inability to read the instructions in her reference. Nichole says to,

"Screw the pieces together with 1 1/2 inch wood screws spaced every 3-4 inches. To make it easier to put the screws in, make a pilot hole with a drill and 1/8-inch bit for each screw."

Would that Liandi had specified a size for the screws (a ¹⁄₈-inch bit is the right size for a #10 screw's pilot hole) and, more to the point, specified a shank size and a countersink size. Her reference said nothing about it either, but her reference did say to use drywall screws instead of wood screws and also said quite clearly,

"After pre-drilling the holes, we squeezed plenty of carpenter's glue between the pieces. The glue, not the screws, is what will ultimately seal the box, so don't be afraid to pour it on."

Nichole, on the other hand, seems to think that the screws will hold everything together. Here's a hint, Nichole: they won't. Oh, and your reference (which you don't seem to have read) also said that it's a good idea to brace the joints because, and we quote, "The box will be subjected to extreme internal pressure, so the stronger it is, the better."

So no, Liandi is not an "expert" despite having published at least five articles about subwoofer boxes (only one ported). In fact, she's about as far from an expert as you can get: she's our Dumbass of the Day.

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