There are however, some very fine dedicated subwoofers such as the best models made by Velodyne using accelerometers in a feedback loop. Loudspeaker of any type whether called subwoofers or not that can accurately reproduce the lowest octave at reasonably high volume with low distortion are few and far between and usually very expensive. But they do exist.

The problem with integrating them with "satellite speakers" is in the transition range. In a well designed sound system, the low frequency unit makes a reasonably seamless match in both phase and frequency response. However when one subwoofer in one location is used with two satellites several feet away, they often created very irregular phase and frequency response that is exaggerated with peaks and troughs all over the place. The best way to use subwoofers IMO, it to buy two of them and locate each one as close to a satellite as possible. This in effect is what you get if you buy a full range tower system such as JBL S412p or recently available AR1.

The test of deep bass are organ pedal notes. Digital recordings on cd work best. On a real pipe organ, those notes are very deep, pure, and are felt. There are very few loudspeakers in my experience which can duplicate those tones accurately.

I think it is outrageous that a manufacturer sells you a pair of supposedly high fidelity loudspeakers for $1500, $2000, $2500 or even more and then tells you if you want to hear the bottom octave, go out and buy my subwoofer for another $1000 or more. That stinks.

One of the most frustrating things about deep bass is not only speaker placement but listener placement as well. Moving the speaker several inches can make a big difference in what you hear. So can moving to another spot in the same room.