It will sound like a 4" coaxial with sharper tones and better imaging, of course it will require a high cut off point because of the small driver size but with todays subs it could sound quite nice, your midbass will pull towards the back more is all.
Give me a couple of weeks and I'll give you a small review of my Rainbow 4'' Pro's. I just have to get around to making some kicks //content.invisioncic.com/y282845/emoticons/rolleyes.gif.c1fef805e9d1464d377451cd5bc18bfb.gif
Hey there check your PM box -- you will never get awesome midbass from a 4" but you make do with what you have //content.invisioncic.com/y282845/emoticons/smile.gif.1ebc41e1811405b213edfc4622c41e27.gif