if your going for a sub in the boot, id advise you dont have 6x9s at all,
in they're most common application, theyre pretty much useless.
the rear speakers are easy enough to wire in, just run two wires either side to the connectors.
i wouldnt bother going for an external amp for the rear speaker, the amount of extra wiring, and space taken up by the amp far outweigh the perks, also it really depends on the speakers your using. for the likes of fli speakers, id say its a waste of money.
at a quick glance. the 12" flis offer 300wrms at an impedence of 4 ohm, so you would be looking at a monoblock around the 800wrms @ 2ohm range for the amp, the wire the sups in paralell to create a 2ohm load. i wouldnt personally bother getting a stereo amp for subs as theyre not designed to be abused in such a way and you dont listen to bass in stereo anyway. dont be fooled, a single channel amp does not mean it can only take one speaker, it simply means it only creates one signal, which can be split into many speakers providing the wiring is correct. make sure you match the amp to your speakers, or it will sound shat! id try and find a jbl 1201.1, rated 1114wrms @ 2ohm single channel. It would laugh at most subs you would use and is amazing value for money. (if you can find one nowdays
)
another point, dont be a n00b if you get another amp and simply split the power wire into two, because you will create a draw thats too high for the wiring. im guessing from the ease of fitting you used 8awg wire. personally i wouldnt use that for anything, so update your wiring to 0awg asap if you plan on going big. (and 1kwrms counts as big)
HOWEVER personally if you want to get big into your audio, i would sell the fli sub complete and start looking at some higher end gear. Hope this helps.
