The Energy's are big in size they remind me of MB Quarts they are a true 6 1/2" not 6 " like most.The 6" X 9" are really big and needs some cutting to make them fit,but well worth the cutting I tell ya.As far as sounding a tad bright I would say that depends of the location of the tweeters and the setting on the crossovers.
Remember when mounting a tweeter up high in the door or close to the window you will get reflection off the window so your going to go -3db on the tweeters anyways.They sound awesome mounted in the kickpanel and done the way real sound Q should be they sound great.I take a small 2 channel say 40 x 2 or 50 x 2 bridge it and run it mono.One mono set up on each kick panel,this way both amps are in mono and are seperate from each other no chance for cross talk between the two channels or should I say between the 2 kick pannels.Oh and did I say you will have lots of power I'm talking like 150 to 200 watts on each lots of headroom.I know now I sound like Tim Allen lol.