Ok fellas, let the record show, he asked for this!
Just kidding,
@Toolmaster Of Brainerd , you didn't really ask for ALL of this. But you're gonna get it.
I've made a few cabs now, recently finished these 1x12's to pair with my also new Sweet 16 LTD head, and a couple years ago I did a tall/offset speaker 2x12 closed back to match with my Custom 50.
The 1x12's
The 2x12
So, yes, you can successfully build cabinets... I mean, I did it!
BUT
You need to know what parts you need, and have a solid plan, or they can become expensive in a real hurry! I'm talking buying parts just to see what works, not knowing what to get, etc. Like
@sergiodeblanc said, that stuff adds up fast.
StewMac may be a good source, but their upcharge for what are not actually expensive parts is often pretty hefty. I did most of my parts for these as a combination of AmplifiedParts, Mojotone, and a local Ace Hardware with the world's most kick@$$ hardware selection of fasteners, etc.
This is probably going to be way more information than you really hoped for, but if you decide to undertake this project, please read on, because it'll save you a boatload of money.
First, cabinet type and materials - basically, you have 3 types: Closed back, open back, and ported. In a closed back cab, the overall volume, as well as the specific dimensions, can influence the behavior of the speakers and the overall tone. Open back cabinets generally don't impart much tonal influence, they're just a box that holds a speaker, and since they're open, their enclosure is... Earth's atmosphere. Although materials, resonance, etc. can play a part. Ported cabs are like closed cabs on crack, don't go there unless you have a build plan for a time tested design, because tuning the porting is a complex science at best, trial and error at worst, you don't want to go just "winging it" for the first time unless you have a specific blueprint.
Closed back (and ported) cabs are usually made from birch plywood. It's sturdy, and effectively kills all resonance, especially as you increase the number of plies. The goal with most closed cabs is to defeat resonance of the cabinet material itself, and rely on the internal volume and internal dimensions of the cabinet to influence the response of the speakers. Open cabs, on the other hand, at least the most respected ones, are usually made from solid pine. Being open, there's no internal air space to influence the speakers. Whereas the laminations of plywood kill resonance, solid pine will resonate, so you get some influence there. All of that being said, of the cabs I've made, all have sounded really good, and I basically picked the dimensions without calculating EQ influence (more on that in a minute). The two most important things to choose are
speaker type and
cabinet type. You should pick the kind of enclosure you want, open or closed, and what kind of driver you want in it. The rest does make a difference, yes, but not as much. Closed cabs are usually punchier and fuller in the bass, open cabs are usually brighter on top and skinner in the bass. Put another way, closed cabs are often the choice for hard rock and metal, open cabs for lighter styles, but that's a generality. When it comes to mathematically designing dimensions of a closed back for tone, it's kind of a crap shoot, unless you want to get into some pretty heavy physics and digging deep for speaker specs, and even then, it's minutiae compared to open vs. closed and speaker types. Guitar speakers are incredibly "colored" frequency filters compared to something like PA speakers, and have less linear EQ response over their volume range, so manufacturers like Celestion often don't publish all the info one would need to really tune a cabinet mathematically.
Now, into the literal nuts and bolts of a cabinet build...
First choice, how are you going to build the cabinet frame? Finger jointed cabinets (which I think are actually "box joints" in the world of woodworking) are the most respected type for guitar cabs, but not absolutely necessary if you don't have the tools. I made all of mine with plain butt joints, reinforced with a 1.5x1.5" board, with both countersunk screws and wood glue, as you see here:
u.