Hello,
I hope somebody help me with this question, I have the option to plug my speakers to 6 or 4 ohms which is better?, why? if i chose to use 6 or 4 the sound would be better?
You have not made it clear which equipment you are connecting to and that is important.
I will presume some kind of amplifier:
You should try to match the impedance of the speakers. Most are 8 ohms and it is safe to connect 8 to either 6 or 4. You will get slightly more volume by connecting to 6.
if the amps were all the same make, and the speakers that were to be tested on 6ohms and 4ohms are the same. then theres not difference in sound quality just volume, yet heating might be a bit higher for the lower ohms amp.
I have no idea what Polks you own but the LSi series presents a slightly higher load than most loudspeakers. That said, if you listen at responsible audio levels it won't really matter.
Neither will sound better. But the 4 ohms setting will have a lower passive power draw from the wall because it lowers the input voltage.