In an ideal audio-world we all would have at least a 10x10 meter room and no wife or children to disturb us in finding the perfect placement for our loudspeaker.
So, if you have the room (and the funds) to place a full scale speaker, go ahead and opt for one which reaches into the 30 hz range.
I didn't have the room for a full scale speaker and had to compromise a bit by opting for a good monitor speaker (Von Schweikert VR-1's) and added a very fast sub (VRS-1). The integration between the monitors and the sub is excellent and you only hear the sub when you switch it off (the podium becomes smaller)!
So, adding a sub might be a good idea, but speed is important. Another thing, since you'll be running the speakers full range (no low pass filter on your stereo amplifier I hope) you want to set the crossover of the sub low. I've got the VRS-1 at 50 Hz, but the roll of is only -12 db/octave which might cause some mid-bass overlap with full-range speakers.
So, if you have the room (and the funds) to place a full scale speaker, go ahead and opt for one which reaches into the 30 hz range.
I didn't have the room for a full scale speaker and had to compromise a bit by opting for a good monitor speaker (Von Schweikert VR-1's) and added a very fast sub (VRS-1). The integration between the monitors and the sub is excellent and you only hear the sub when you switch it off (the podium becomes smaller)!
So, adding a sub might be a good idea, but speed is important. Another thing, since you'll be running the speakers full range (no low pass filter on your stereo amplifier I hope) you want to set the crossover of the sub low. I've got the VRS-1 at 50 Hz, but the roll of is only -12 db/octave which might cause some mid-bass overlap with full-range speakers.