Antenna Wires??

I just installed a roof mount antenna, and i hooked the big antenna wire to where the stock wire is. The question is… there is also a red wire marked (+) and i’m wondering if i have to hook that to my ignition power??? The radio works fine now, but i wonder if it’ll be even better if i connect this (+) wire.

Anybody know???

probably an amplifier, hook it up to any 12v power source, I would hook i up to the head unit’s remote wire (if you dont have a system)