After a lot of trial and error, research and wasted $$ I ended up with a very simple active 2-way + Sub set up. High quality 6.5" CDT drivers paired with Image Dynamic' 28mm tweeters up front, 10" JBL sub in a ported enclosure in the trunk (no rear speakers). All processing and time alignment is done by a Pioneer deh-80prs HU with the scoshe bezel. Alpine MRX-F30 bridged to the mids, Alpine PDX-5 on the tweeters and sub. Doors are deadend and sealed with CLD and aluminum.