Don't know why you wouldn't have had luck with it before. It's simple, you just damp first reflection points on every wall, and sometimes ceiling and floor. I enjoy ASC traps, and also use RPG and other foam. My basement is concrete also (not in there now, but need to go back in the next month or so). You really do need carpeting on the floor, though, cause you'd really have an echo chamber without it.........I wonder why so many guys are reluctant to do this; it's not as if an untreated room does anything but mask what's on the recording anyway.
Acoustic Treatments
I need some opinions on the above, my listening room is a partially finished basement with floor joists for a ceiling but the front wall behind the speakers is finished. One side wall is framed out and the other is cement with insulation (foil side out). The side walls are 5 feet from the speakers. The system sounds pretty good in this room (I've had the same in 2 other rooms). I noticed a big improvement when I hang damping material on the front wall between the speaks like a wool blanket or oriental rug. Can I improve on that with RPG or Sonex or the like (I know it will look better). I know tuning the room is critical, I've just never had much luck or inclination to do so. Any thoughts would be greatly appreciated!