Speakers vs. headphones

OK, desperation is setting in (I'll admit it). I have a 12-by-13 room with 7-foot ceilings (carpeted room and acoustic tiles up top) and I've tried every speaker and sub placement imaginable for my very modest system (NAD 326 amp, Totem Mites, Velodyne SL-800 sub). Even without the sub, I can't get the sound to anywhere near what I'd like it to be. I had an even more basic system (NHT Super Zeros, Onkyo amp, M&K sub) in my old home and it sounded INCREDIBLE compared to what I have now. Like I said, I've tried diagonal speaker placements and everything else, including room treatments (panels on first reflection points – no bass traps yet, but it seems the problems go well beyond bass). The question(s): Is it time for headphones? Is it even possible to get decent sound in a room with these dimensions?