That is tuff unfortinally you need mass to move air that is really the bottom line. Now without getting into acoustics to much monitors and wall speaker usually don't have much bass because of the size and the fact that if you add bass the speaker becomes more bassey without accurate bass and just sounds worse. If you add a sub you have the problem of the sub not amplifying the same as the speaker and the bass getting heavy at some volumes and light at others. But you will need a sub and that is a expensive speaker.
Vanderssteen has solved this by using a crossover on your pre amp out to cut the bass form the mains and send it to the sub. they also connect the sub to the speaker out so it gets amped the same. You can pick up a 2w pretty cheep 500 or so and add that the trouble is there is a little set up involved. Not sure if other subs do this.
Hope this helps, also placement will effect your bass allot try to keep the speakers away from walls and out of a cabinet.
Vanderssteen has solved this by using a crossover on your pre amp out to cut the bass form the mains and send it to the sub. they also connect the sub to the speaker out so it gets amped the same. You can pick up a 2w pretty cheep 500 or so and add that the trouble is there is a little set up involved. Not sure if other subs do this.
Hope this helps, also placement will effect your bass allot try to keep the speakers away from walls and out of a cabinet.