im going to be running mb quarts 218.61Q comps up front and mb quarts rkc 116 coax in the rear ... the amp is going to be rockford 750x putting out 90 watts RMS x 4 at 4 ohms. my question is do i need a capacitor or a hi amp alternater for this setup??? any replies would be helpful thanks in advance.

 

doubt it

You shoudl be able to run fine without either of those

but if you rewally want, higer amp alternator > cap

 

yeah dude, like he said, you should be okay as is