Thread Focusrite Scarlett 2i4 setup

Hello,

I have just recently bought Scarlett 2i4 audio interface and I would have a few questions about setting it up correctly. These answers were probably covered before, but I couldn't find any "useful" answers, so I decided to create a new thread.

1.) The interface has 4 outputs, where there are one pair of "balanced" outputs in the back and two pairs of "unbalanced" outputs. I have 2i4 connected via USB to my computer using WinAmp or Foobar2000 for mp3 audio playback. On the other side I have Yamaha AX-497 stereo amplifier and a pair of Cerwin Vega XLS-215 speakers. I am wondering which outputs should I use: balanced or unbalanced? What is the difference really? I tried to connect both and I actually can't hear any difference, or is it just me?

2.) The second question I have is: how is it possible to activate unbalanced outputs 3/4? I can use 1/2 balanced or unbalanced as mentioned above, but there's simply no signal output on unbalanced outputs 3/4. So, I am wondering how is it possible to use those 3/4 outputs with a simple audio player (winamp, foobar2000)? Also, would there be any difference from using outputs 1/2 or 3/4?

3.) This question is not directly associated with 2i4 interface but I'll try to ask it anyway. The Cerwin Vega spekaers I use are certified as 6ohm impedance speakers. On my Yamaha AX-497 amplifier there's a switch on the back with left/right option where left is "A or B 4ohm min /speaker" and right is "A or B 6ohm min /speaker". Which option should be selected? What would be the difference actually? I curently have it set to right (A or B 6ohm min /speaker), which was set as factory default...

That would be everything for now. Thank you in advance for your answers!

Best regards...