Subwoofer with Floorstanding Speakers?

You have to get the right sub. For example you may want to avoid home theatre subs (like ported subs). You may want to avoid slow subwoofers that stuggle to stay fast enough for matching speakers. You may not want subwoofers that don’t have enough connections or controls to match your electronics and speakers. You may also want a servo subwoofer which is a fast amplifier and signal sensing system. Also don’t over power the room with the wrong subwoofer. I chose Rythmik subwoofers F12 SE for my Vandersteen speakers. The amp I have is a Parasound and it has RCA outputs (variable) for the subs. I had full control to blend the low freqs. I have REW but have not used it.

I have four subs (3 Rel + 1 SVS) that supplement my floorstanders (Vienna Acoustics Mozart Grande). Adding the subs is the best thing I have done in many years to improve my listening experience.

I run subs with large speakers. Without the subs my system is just ok but with the subs it is outstanding. Bass really matters and does make a huge difference  

All speakers need subs. Even wilson audio runs subs with their supersize speakers. Unless the speaker is active all speakers improve with subs. 
 

With big speakers you need to use a highpass. If you look up the measurements of your speakers and cross them over where the woofer starts to roll off before the port picks up (probably 60hz) it will work out pretty well as a starting point. 

I run an active sub with floor standing speakers to augment only the bottom octave.  The sub runs off the main speaker outputs to the high level inputs, and the low pass crossover gets set at its lowest setting (<50hz).  I do not run my main speakers through the high pass filter of the sub to avoid any degradation to the signal, and I set the gain of the sub very low so that it's barely audible.  My intent for the sub is to augment what the floor standers do, not feature it.

There are really two possibilities here. One, you do miss actual low bass… but more likely your memory was flabby over highlighted bass. Better audio systems have much more accurate bass, which can contrast with college.

However, subwoofers will add bass. Always add in pairs… this will also help extend the soundstage as well. When I had Olympica I had a pair. Although mostly what they did was increase the soundstage. I happily got rid of them when I upgraded my speakers.