Are you planning on wiring all 4 speakers to one binding post of an amp? If so, you will have a 2 Ohm load on that channel.
Yes, 2-16ga wire in parallel will be 13 ga.
Yes, 2-16ga wire in parallel will be 13 ga.
OK. Now you have a 4 Ohm load if they are on one terminal. Will amp handle 4 Ohm loads even if the background volume is relatively low most of the time.No, it’s A/B on left channel and C/D on right