I came from exactly where you are...I got a 424MKIII and I wanted to do just what you are doing. Well, after playing around with stuff I found the most suitable method. As for channel 5 and 6 go, all I know is that they are line level channels, meaning you have to use the 1/4" inputs. I think you CAN set the channels to get input from XLR 1 - 4, but if you're already using those inputs...then...That's all I can tell you about em. Oh, and obviously you can't do Direct record from them, so you have to pan em left or right to record onto one of the tracks. I guess I would say use 5 & 6 for drums. Now, as for live recording...yeah, it sounds good at first. BUT it's a pain in the ass in the long run. One, everything has to be hooked up all at once. Two, you're recording 6 sources onto 4 tracks...this means you're going to have to do all/much of your EQing up front and put two or more sources onto one track. This eliminates the option to re-EQ something later. Example, bass and drums (both inputs) onto track 4. A few days later after listening to the mix, you decide the bass is too quite and not deep enough...too late! See what I'm saying? Now this holds true with recording each source seperately, but when you're doing that, you have more time/leeway/control over what's going where and how it sounds. You're most likely going to want to put both guitars onto one track, since the sound and EQing is pretty identical with two guitars...a lot of people (with 4 tracks) put drums and bass on the same track, vocals of course get their own...that gives you one free track. OK, now split bass and drums, or guitar and guitar? It's up to you...
As far as equipment needed...well...of course you're gonna want the ever-popular Shure SM57s (one for each guitar amp). But, you don't have to do that. You could always plug the amp direct into the 424...WARNING WARNING WARNING. Do not do this unless the amp has SPECIFICALLY a "Line Out" jack...Headphone, External Speaker, etc. will not cut it...and you'll regret it. You might even wanna put a direct box between the amp and the console. I personally like using this method, mainly cause I cannot get that guitar sound I want with a mic'd amp (maybe I just need more patience. For bass, the most common method is just plug the bass (not necessarily the amp) into a direct box and then to the 424. It eliminates the need for the bass amp, and you'll most likely get a better, thicker sound this way, plus save $100+ for a seperate bass mic. HOWEVER, many people report excellent results using an Art Tube MP (mic preamp with a tube) as a bass direct box...makes sense. It adds warmth to the already deep tone. That's gotta be good. Also, the Tube MP comes in handy for vocals, especially on cheaper mixers like the 424's built in one. Drums? Two overheads is all you can really have with that 424 doing it live. Two RODE NT1s if you are on a budget ($169 each from zzounds.com, cheapest you'll find em). Vocals? Well, do you HAVE to do em live? If you can compromise, record all the music at once, then vocals last. At least you won't have everything leaking onto the vocal track. For the vocals, use a RODE NT1, and an Art Tube MP if you get one. This is a more tedius and expensive project than I ever imagined...it takes time, patience, and of course musical talent
Let me know what you think of this...Don't overlook recording everything seperately. If you guys are just recording a song for fun, all you need is a condensor (Rode NT1 as I suggested) or 2 sitting in the middle of the room, or about...that'll pick everything up. For recording a demo, you're going to want to record seperately. Trust me, this is what I ended up doing with my band.
And yes, it is possible to dump the song to the computer. What you need is a WAV file recording program, and a 2 RCA to single 1/8" cable (you can find these most anywhere). Plug the two RCA cables into the 424's Line Out, and into the computer's Line In, set Windows Sound Properties to record from Line In (instead of Microphone which is the default), hit play, and record on the computer.
Let me know if you need anything else! Sorry about the long message
