You could as long as you don’t want to use time code. The certified mixer thing only matters for Traktor Scratch. But, you’d only be able to use 2 decks, not 4. To use 4 decks, you need 4 stereo outputs. Traktor doesn’t like sending out mono signals…at least not when I tried it. So you can’t even really do that.
The cheapest ways to do that are to either get an older Audio 8 DJ or a second Audio 2 and build an aggregate device. Note that the later only works on OS X and isn’t ideal…but it is cheap and does work.
Also…I mix with a pair of X1s and either a controller or a mixer. Love it. But I’m pretty far away from the default mappings.
X1 #1 controls decks A and B, which are full track decks. Everything from the Browse knobs down is mapped as normal except that the Browse knob’s shift+push control also selects a specific favorite playlist slot when it switched to the only browser view. Loading a track also turns off only browser view. Oh, I also un-mapped the FX1 and FX2 on buttons for both decks.
I also ditched all of the effects controls when I realized that I never use them.
The knobs are 4-band EQ controls over the software xone EQ. Shift+button 3 unloads either deck A or B if it’s stopped. Buttons On, 1, and 2 don’t do anything right now, but they’ll probably end up controlling the browser in some way. The 4 lights (buttons on, 1, 2, 3) on the left are pre-fader level meters for my 4 decks…mostly because it’s pretty. The 4 lights on the right are a 4-segment master level meter, and I have a separate mapping for using an external meter so that they’ll turn on when I’m running out of headroom so I can avoid clipping my sound card outs without using Traktor’s limiter…which sounds like tin cans and a string.
Adding those level meters and ditching effects means that I don’t ever look at the laptop when mixing…only when loading tracks/samples.
X1 #2 controls decks C and D, which are now sample decks. Basically, it uses the default mapping with some changes. First, the 8 knobs at the top control slot levels instead of filters. The buttons still turn on/off filters, and the filters are controlled by the select functionality (shift + even numbered hot cue buttons) and the browse knob. Basically, I just swapped filter and level controls because levels are more important IMHO. Shift + the buttons at the top sends the slot to the headphones. I’m not quite done yet…as I’d really like to be able to browse and load samples from the controller…just need to find the right places to put it. I’ll probably end up moving the filters down to the loop encoder and returning the browse encoder to its normal function. I’ll probably do loading with the hotcue buttons or something.
And as a mixer, I usually either use my lpd8 (because it’s small and I like rotary mixers) or my xone:62. Because of the way I like to use sample decks, though, I’m about to try to sell the xone and my vcm to get an Empath Rotary, 'cuz I’ve always loved the empaths and want a rotary. 3 channels would be perfect for the way I use Traktor.