This set i posted above will give you the desired bass you want. Honestly these headphones feel like they have a built in sub.
If you do decide to take in the plunge, consider doing a speaker Burn-in/Break-in, since they are high end.
Very often new components will improve considerably with use. The break-in period varies considerably depending upon the product—from as little as a hour to as many as hundreds of hours. Your owner's manual may have specific break-in instructions; if so, we suggest that you follow them. You can accelerate the break-in period by playing your system while you're not home. Using a tuner or a CD-player set to repeat, just start the system when you leave. Listen periodically to the system and stop the break-in when you notice no further improvement.
For speakers and some analog cables with networks, the volume that you use will be important. For the first few hours, keep the volume low. For the next dozen hours or so, use a moderate volume. From then on, use a higher volume with music that contains wide dynamic contrasts. If you are in a hurry, you can accelerate the speakers' break-in with a special procedure:
Further details if required:-
http://www.head-fi.org/t/56744/headphone-burn-in-faq




