can i run my 6x9s and a single subwoofer off a 4 channel amp

does it matter that theres a channel not being used?

 

it depends on the amp, you should be able to use two channels for the 6x9's and bridge the other two for the sub (check the amp hand book before doing this,it could end badly if you don't do it right)

 

I would run one amp for the 6x9 and get another one for the sub

 

ok

 

i will be getting it fitted so this should be ok?

 

It wont matter not running 1 channel mate, as said use bridge chanells. something like chanel 2 for 1 6x9 chanel 3 for the other then positive off chanel 1 and negative from chanel 4. wil get nore power to your sub then, or if using a seperate amp get a monoblock amp for sube and either bridge the 6x9s or run in series

 

I would run the 6x9's off the headunit, and use the 4 channel amp to run front speakers and a sub as mentioned above by bridging 2 channels to give a single more powerfull channel for the sub (amp dependent as to this being possible). 6x9's aren't the best solution and amping them without doing anything to the fronts will give you noise but not a nice sound

 

This mans got it!
Sound from the back sounds nasty, get a decentish set of fronts and amp them leave the 6x9's for rear fill (if you have to have them) and it'll sound alot better.