There way to many questions for me to state in the subject title.

1. I am getting an audio system for my iMac, most probably 2.1 would be good. Considering the M50, but do I need other stuff to connect my iMac to the M50? I don't exactly know how it work.

2. Is a receiver a must for floor-standing speakers?

3. Do I still need a bass subwoofer if I choose floor-standing speakers?

4. Lastly, simply using it for music, using an iMac, what would be the best speakers and what would I also need?