PROAC D48R Bass Booming

gnanasekhar,

One more thing to consider--if the floor in your listening room is a suspended wooden floor, the floor could be acting as a giant sounding board which could be at least part of the problem.  With such flooring, the speaker should not be coupled to the floor (e.g., by using spiked cones), and instead, isolating footers or platforms should be used; you want something that will absorb/damp the bass energy that is shaking your speakers rather than coupling that energy to the floor.

@gnanasekhar,
Are the speakers placed in front of the long or short wall?
Can you move them 24" from the side wall? Also Can you move them 50" from the front wall. Also try with the classic ProAc toe-in; which is to angle at the listening position with the "inner" side wall slightly visible from listening position. If that does not work, try to aim them straight ahead.
Looking at your profile, I think you have marble/til floors and thick concrete walls. So bass trapping in the corner will also help. The bass on these babies is certainly not "loose". It is super tight if the right.
The IsoAcoustic Gaia II will certainly help providing definition to the bass.Try to adjust the speaker position. The more you get it "into" the room, the less bass. Do your best before your decide to part away with this PHENOMENAL loudspeaker. Good luck!

@milpai 
The speakers are placed in front of the longwall and are placed on Tile floor.  What about the Herbie products

Another possible suggestion is to place the speakers asymmetrically in the room. Have one speaker places closer to the side wall than the other. One speaker closer to the back wall than the other. Move the listening position so that the speakers are equal distance from the listener and the listener is facing between the speakers.

The logic behind this is to not place the speakers in a position to reinforce the bass by interacting with each other.

I personally use a set up similar to what I have described including the use of five large leafy artificial plants behind the speakers. It took the bloom / boom right out of the room. Tone balance, timing, dynamics, imaging and detail is now superb.

@gnanasekhar ,If the speakers are in front of the 17' wall, then you have more than enough room to pull them close together. You can easily pull them 4' (each side) from the side walls and still have 9' between them. Which tells me that you can have the flexibility to pull them 4.5' from the side walls, and about 36" from the front wall. This should reduce the boom. In this position, your chair should be almost up against the back wall. So a pair of Monster panels from GIK (or other equivalent product available locally) should help you reduce the overall boom.I have got great results from Herbies products. Email them and ask for recommendation. My guess is that one of their product will help "tighten" the bass. Ask them for a product that can be used with the speakers spikes. Alternately ask them for suggestions, to place the speaker on a product with the spikes removed, since you already are on tiles.Is this a closed room? I remember a thread where you were guided to @jperry room (with similar dimension as yours and he has D40R). But I believe that @jperry room opens on the other side into another room. So the bass waves have more room to dissipate.Do keep us posted on if you were able to change the speaker layout and the results.