i have pioneer in my alfa, there follows an adaptor with to the the front speaker.
cerwin vega 6x9 rear speakers.
then a 12" cerwin vega 800w sub in the trunk.
to the sub i use a rubicon amplifier (bridge)1x400w rms, and to the rest i use a 4 channel
phoneix gold amp(4x 50w rms)
headunit i have a panasonic 888 with 4volt output, and a seperated sub output.
real nice sound
We list these at the www.alfaowner.com/shop there is a little popup also telling you which speaker goes where and ordering online is easy. We stock Kenwwod as these were extremely impressive for the price, also its a brand name and you can trust that they will be good!