[posted back in 31st July 2012] I can't say that I'm a DJ or a Radio Jock (I've got a horrible apek voice!) but I do dabble a bit in playing music for anyone who wishes to listen, get paid well for what I do too but doubt any of my readers wants to know that. Anyway, some of my friends was talking about finding cheaper alternatives to some devices to work along with the Traktor Pro we uses for shows and at the clubs because the Traktor Audio4/6/8 even the Numark DJ I/O USB Audio Interface isn't cheap especially for part time Deejays to use.
Well, there is a solution which I've been using for a good 2 years now. Personally this is what I've been using for at home and when I don't have a proper Mixer to plug my computer into. At most times, I uses a Numark Mixtrack Pro 2-Channel DJ Controller which is more than sufficient for what I do. Some friends uses the later models like the Traktor Kontrol S4 which is a nice little device. The reason I mention these systems is because most Retailers would try to encourage you to buy a USB Audio Interface which is not cheap in Malaysia to go with the Mixers. So what are the alternative? For me, I uses a cheap RM99 Soundblaster X-Fi Go! Pro It might look cheap, USB looking stick jutting out of the Macbook into the amp (when there's no mixer for us to patch our music through but heck, when there's a need to be portable, why not right? I still can use my audio output on the MBP as my monitor and the X-Fi as my output to the speakers.
Now, the problem a lot of Traktor users face when they uses a soundcard like this instead of the 'adviced' USB Audio Controller is, the Traktor doesn't really recognize the device and there's a bit of CHEAT you have to do to trick it into reading your device as the way you want it to. This is especially useful when you are just using the Application without the Mixtrack or Kontrol S4. Here's my simple how to do it ...
1st up, most important, install your Sound Blaster X-Fi! For the latest OS, it should detect and auto-install without any issues, if not, there's the driver files inside the USB itself for installation. Quite a number of people I know actually came back to me saying that it doesn't work after they plug in the USB drive. Well, you'd have to install the driver for the computer to recognize it, or else, it'll just be a USB drive sitting there looking pretty. Do note that the setting I'm doing here is for Mac OS but am sure there's similar way to do it for PC. Once you have the X-Fi installed. It's time to create an aggregate device, you can use more than one audio interface at the same time with audio applications like Traktor, Soundtrack Pro, GarageBand, or most other Core Audio-compliant applications.
From there, just click the + sign and an Aggregate Device tab will appear. On the right side, just select/check the devices you want to use, in this case, it's the X-Fi and the Build-In Output (so you can use one as Monitor and the other as your Output to the speakers). Once that is done, close and go to the System Preference, Select Sound. In the Output tab, you'd be able to select the output that you want, in this case, it'll be the Aggregate Device. Select that and you're all set.
All you have to do now is do a minor configuration on the Application itself so turn the Traktor Pro on and it will then go through it's usual auto-detect thing. Once that's done, go into the Settings, the first thing you should do is, Audio Setup, at the Audio Device Column, you should then select the Aggregate Device that you just created in the steps above.
Once that's done, go to the Output Routing and select how you want the audio to go out of the computer. In my scenario and the sake of this 'Tutorial', the X-Fi is my main output and my Monitor is the MBP's Headphone output. The reason for it is because as I move about, the wires of my headphone is bound to jiggle about and if it is hooked to my X-Fi, half the time the sensitivity of the USB connection would be interrupted which will then annoying trigger the Traktor Pro to prompt for reconfiguration. And if you are doing a LIVE set at that moment, you'd end up disrupting the music and get booed!
So, in my scenario, Aggregate Device Out 2 and 3 represents the Left & Right channel of the monitor (headphone). The Aggregate Device Out 1 and Front Left is of course the connection to the Amplifier (if you are not routing it into a Mixer), note that I place the Channels wrongly in the Master Output where the Front Left should be the Left Channel and AD Out 1 should be the right. You get the drift right? All in All, with that setting, you are all set to go, even if you didn't have your Traktor Kontrol S4 or MixTrack Pro or Pioneer DDJ ERGO. You can still play and mix your music off the computer without any issue with the right output into your headphone and the speakers respectively.
Another important thing, do update the software and the device plugins as there has been issues with the older Mixtrack and the S2 when it comes to compatibility when I use the X-Fi instead of the DJ I/O which seem to disappear after I update my Traktor software. Those of you using the Traktor LE can also get a free upgrade to the Traktor Pro now too (I think it's for a limited time only). Another thing is, try to invest in a good USB or FireWire Cable if you wish to hook your MBP to the Pioneer CDJ-2000/Pioneer DJM 900 Nexus as the sound is just totally different from using a normal off-the-shelf USB Cable.