Here is a link that contains a table of resistance per unit length (ohms/kilofoot) for the different wire gauges:
http://en.wikipedia.org/wiki/American_wire_gauge
You will see that 14 gauge is about 2.5 ohms per kilofoot, which would be about 0.2 ohms for the 80 foot two-way path that you are dealing with. That seems reasonably low in relation to an 8 ohm speaker, especially in a surround application. If the speakers have significantly lower impedance and/or good bass extension, a heavier gauge may be desirable, as the others have noted. The table may help to give you a feel for how much each increase in gauge will provide in terms of lowered resistance.
Regards,
-- Al
http://en.wikipedia.org/wiki/American_wire_gauge
You will see that 14 gauge is about 2.5 ohms per kilofoot, which would be about 0.2 ohms for the 80 foot two-way path that you are dealing with. That seems reasonably low in relation to an 8 ohm speaker, especially in a surround application. If the speakers have significantly lower impedance and/or good bass extension, a heavier gauge may be desirable, as the others have noted. The table may help to give you a feel for how much each increase in gauge will provide in terms of lowered resistance.
Regards,
-- Al