It is not hard to get good tone - it just has to be done right. I built some gtr cabs. The first one I built of plywood from a lumber yard. It sounded dull and thuddy. My buddy recommended void-free birch plywood at 2X the cost. Built one from that and it was fan-damn-tastic!

Construction technique is the hard part, and you've got that covered. Calculate your dimensions carefully to construct a "sound" that you want. Only you can decide that.

OK, maybe my reply isn't too helpful, but I just wanted to point out that it can be fairly easy to do it right if you've got the bases covered.

Good luck!
-Johntodd

I can't see any reason a home-built 1x12 will lack character vs a 2x12 - especially, as John says, if you use proper hardwood, which is the main consideration.

I certainly have a few custom 2x12s built by a company called Zilla out of ply - whether it is void-free or not, I couldn't say and would doubt it - they outperform by a long shot a similar Marshall 2x12 made from chipboard.

We use a chipboard Marshall 1x12 with an Orange Tiny Terror for recording to add flavour to layered guitar tracks and its a very pleasing, compact and warm sound so follow the dimensions of most manufacturers and as long as you are going to dovetail it properly and give a decent mount for the speaker itself you should be fine. Jimmy Page used to record with a 1x12 I believe so you are in good company!

I've always been a 4X12 man, myself. I grew up during the "metal years", so big stacks are my thing. However, experience has shown me that more speakers are better even at lower volumes. I can't quite put my finger on it; I've been stewing over this for 20 years; but I think it is because no two speakers are exactly alike. To me, more speakers = more character, but simply because each speaker has it's own way of doing things. But I must concede that the differences will be subtle, at best.

If you only close mic, you lose this character due to the mic picking up one speaker. But to mic a whole cabinet in a mostly dead room can be a glorious thing. So, I've taken to putting a mic close up for the direct sound, a mic back a bit for the whole cab, and a mic across the room pointing at a reflective wall for ambiance. Record all mics on separate tracks and mix to taste.

Please keep in mind that these are the opinions of an artist. Engineers can always argue about frequencies; I always have to look them up on a chart! My opinions are just that; your mileage may vary.

The main difference between your 1x12 vs a 2x12 or 4x12 (other than the cabinet's resonance) is that multiple speakers in a cabinet tend to create some phase issues between each other, resulting in various amounts of comb filtering at various frequencies depending on where you are listening from. The multiple driver cabinets sound bigger not only because they are louder, but also because of that. However, if you are recording, you'd generally shove the mic right into one speaker, and not get that effect to tape...

Late to the party, and you've probably already built it (If you did, please send photos) but...

I recently built a 1x12 open back. (Yours is an open back, right?)
It works great despite it's simplicity. Sounds as good if not better than the combo.

3/4" Birch ply
1/2" sound board (I've been told that if a sound board is too stiff, it can sound stale. I can't see how that's possible, but I did it anyway.)

You can buy feet, handles, and tolex if desired in packages.

PS. For close micing, I can't imagine the number of speakers would make a difference. However, many are adamant about larger cabinet sizes sounding fuller.

If you understand the wood and the dimensions, I would say you'd be perfectly fine with one 12 inch. If in doubt, go for two, but you said you researched it. Typically all a 2x12 or a 4x12 (what I have) do is allow the speakers to interfere with each other. Good luck.