I have several realtrap HF ceiling tiles in my basement hometheater. Primary to address ceiling first reflection points for my center channel speaker. The realtrap tiles are very well made and effective.
However far cheaper I stuffed acoustical cotton insulation batts in the joists ABOVE my suspended ceiling tiles. (
http://www.bondedlogic.com/). It was dusty work but worth it.
For deep bass, the sound goes thru the existing ceiling tiles and hits the insulation which can be very thickly stuffed in between the joists for maximum effect. I then replaced the corner ceiling tiles with wooden square (picture like) frames and over the frames I stretched speaker (acoustically transparent) cloth. This allows some of the mid bass frequencies that might be reflected by the normal ceiling tiles to be passed up into the joists for absorption by the insulation between the joists. Doing the corners is useful because the bass modes tend to naturally collect in the corners.
I recommend that you first treat the area in between the joists above and then if you need further work you look into the ceiling tiles.
One last thing, keep in mind that your room will have several bass modes that are caused by width, length and ceiling/floor modes. Treating the ceiling only effects the bass modes that are driven by the ceiling. You will still need to look into walls and corners for full treatment.
By the way, what is on the main level of your home above your hometheater? I installed new hardwood floors in the living room above my basement hometheater. I used that as an opportunity to lay down a second plywood subfloor with greenglue between the layers. This was to provide better sound isolation but had a very nice bass trap effect.
read about it here:
http://www.avsforum.com/t/1136101/my-bass-story-ii