I could not find the specs on the Alesis 12 only the 8 track version which clearly states stereo out. So this peice of gear can not do what you are looking for unless you track seperately, two channels of input at a time. To record the band "live" you will need something different and not necessarily a mixer. First you need to determine the minimum number of inputs you require (4, 8, 12, 16.) Since you already have a mixer I would suggest an interface. What this does is convert analog signal to digital which is then transmitted to the computer in most cases by firewire (especially if you are running high multiple channels.) These units can have preamps built in (recommended at your level.) Some like the Presonus FP10 and Firestudio Project can be daisy chained so you could start out with eight and add a second unit later to get 16. Check specs carefully for computer compatibility.
Here are some links:
http://www.sweetwater.com/store/search.php?s=presonus+fp10&rkg=1
http://pro-audio.musiciansfriend.com/product/ART-TubeFire-8?sku=180164
There are quite a few other manufacturers. I use Presonus but that is not an endorsement. If you are already fluent in Cubase you might want to make sure the unit is compatible, some only work with Protools. Shop around and let us know what you are looking at and I am certain you will get some feedback.

JG of the Frozen Tundra is right on the nail here. I'm sorry to say the MultiMix cannot be used for multitrack recording, as it has neither channel direct outputs nor insert jacks that could be pressed into use.

A separate multichannel interface is what is needed. If you were to get one that had analog outs on each channel in addition to the FireWire interface, you would be able to connect your MultiMix to these outputs and use it for mixing monitor tracks as you record. Unfortunately, 8-channel FireWire interfaces that have pre-amp analog outs are few and far between. You have to go to something that has a full routing matrix like the Motu 896 to get this property.

If you budget can't stretch to that, you will have to put up with a standard FireWire interface like the Presonus FP10 and monitor via software. However, this method is prone to problems of latency. Unfortunately, the FP10 "zero latency" cue arrangement does not allow individual channel level adjustment in the monitor mix.

You can I belive use the outputs on the back of the Presonus units to achieve the monitor type mix Boswell was speaking of. I use the FS project which has 8 analog outputs on the rear plate these are post preamp but if they were brought in as line level inputs you could use the Alesis as a monitor/headphone mixing station.

The last time I tried to use some creative routing in a FireStudio Project I got very frustrated by what you could and could not do. Presonus could easily have incorporated a mode where all pre-amp outputs were routed to the analog output jacks, but no, you have to futz around by treating the outputs as four stereo pairs and panning individual inputs hard L or R, two to each pair. In any case, these are digitized and re-constructed outputs, not the clean outputs from the pre-amps. Not pretty.

Yeah I wasn't sure that it would work as I have never tried it. I just knew that the outputs exist. So I guess they are coming back out from the Firecontrol panel software then?

That's why I like my FS 26/26.
Lots of input/output options.
You can send 8 analog outs, or use stereo outs to route multiple headphone/monitoring mixes. Not sure if these are post preamp, but I'm guessing they are.
Fortunately, I use a fair amount of external pres, so the gain on the FS is always set to zero.
Plus ADAT for up to 24 inputs (26 w/ SPDIF).

If only I had known I would learn to love cables so much I would have.....(begins drooling.)

Hey I thought I did pretty well when I first invested in an interface to have the knowledge that while I was lookimg for only two inputs like the Firebox that FS Project was only $250.00 more and had eight, but I probably should have turned back then.

jg49 wrote: Yeah I wasn't sure that it would work as I have never tried it. I just knew that the outputs exist. So I guess they are coming back out from the Firecontrol panel software then?

No, the signal routing I was talking about is internal to the interface. You configure the digital data for the DACs to come from the digitized pre-amp outputs and not the DAW returns. In this way, the analog outputs suffer an A-D-A conversion process, but at least they do not have the ignominy of being turned around in the DAW software, with all the latency that that routing would imply.