rephrase:
Can the SX2 work with external soundcard alongside Serato, if not is there a solution?
also... Will the soundcard be compatible in Ableton?

I think you may have it backwards. I think you can use an external soundcard with your SX2 IF it's one that "enables" Serato (like a Rane SL2, SL3, SL4 or Denon DS1) and then use your SX2 as a midi controller.

Many have been drooling at the mouth waiting for Serato to revamp their primitive licensing, so you could use truly professional soundcards. Not there yet, and may never be.

That almost makes you want to cry. Serato, we need your support on this!
Rekordbox doesn't do the same things for me as you guys do...

If you want to use an external dac/sound card, you need to have a digital out. The SX2 doesn't have one. I guess you could buy something that has an AD converter, and then convert it back to analog. Doing it that way would take Serato out of the picture, but unless you were trying to accomplish something specific, it would be pointless.

I do own a Cambridge audio DacMagicPlus… Ill try it out tomorrow and see if I can make something of it.

There's nothing to try. The SX2 doesn't have a digital out and the Cambridge doesn't have an analog input. Its just a dac.

The sx2 runs on rekordbox with the third party soundcard... the problem now is combining the mic through the soundcard and getting that to work

Long story short our mic will only work with ableton only, we fixed this by buying a cheaper active mic for live preformances and recording via the soundcard... we fixed the issue with the software comparability by moving to rekordbox accepting a third party soundcard (serato fix yo sh*t)... tho we are still locked to ableton for recording with the rode nt2a. Thanks for everyone’s help. Please put any further comments below for improvements or further directional help.

There has to be some type of miscommunication here. I don't think we are talking about the same thing. When you ask if your SX2 can be used with an external sound card, that typically means a digital output going into some type of digital processing unit. I have an SX2. There's no digital out on it. I do high end audio for a living and I have all types of dac's and other processors that I would like to plug it into, but I just can't. Its a hardware issue, not software.

After reading your posts again, it doesn't look like that's what you need to do. It looks like you want to record music playing from your SX2 and mix it in with other material using a mic. That's something else, and you can do it with what you have. Plug your SX2 into one of the analog inputs on the Ficusrite. (Serato's control over your music and equipment stops at the analog outputs of the SX2. Once the signal is converted to analog, you can do whatever you want with it.). Then plug the mic into another input of the Focusrite. Both inputs will be converted to a non propitiatory digital format that you can manipulate however your see fit. You don't need to use Rekordbox if you go this route. Serato will work fine.

No. Only one Serato enabled interface can be used at a time. Per Serato. I sent a ticket in months ago cause i wanted to use the WeGo as an add on controller. no dice.

You're correct, but that's not what we're talking about. However, if you are looking for a 2nd midi controller, check out a Novation Launchpad Pro. I use one with my SX2 and have no complaints. I use it to access functions from all 4 decks without having to switch back and forth using the controller that only allows 2 active decks at one time.

I needed a jog wheel controller, but unfortunately serato has none without built in interfaces. One of the many reasons I left serato