You can do it relativly cheap but I wouldnt recommend it. The highs will be pretty loud in your ears and you'll lose alot of the mids and lows. Tweeters are normally directed away from you or at least at a minor angle so they dont overpower everything else and putting them 3 inches from your ears is gonna sound pretty crappy. Best place to have them is on top of the dash in the corner or on the corner of the doors directed slightly away from you.