A: Yes. Most “full-range” studio monitors (especially near fields) in fact cut off at around 40-50 Hz. Many monitors miss at least a whole octave or more of sound, from 20-40 or 50 Hz. The consequence is that a professional in a studio setting not equipped with bass management and a subwoofer may not hear things like low frequency rumble or other low end problems in the mix because his monitors cut off at 50 Hz. The listener at home, on the other hand may hear this information clearly depending upon his or her system. Even though many home 5-channel satellite loudspeakers cut off at 80 Hz, the bass management system is sending the low-frequency content to a subwoofer that extends the frequency of all channels down to around 20 Hz.
Further, if bass management and a subwoofer is not used to monitor the program during production, particularly in studios where multi-channel and/or video type production is being done, electrical summation of the channels may result in phase cancellation when played back on a bass managed system at home. This phase cancellation might not be noticed under the original monitor conditions, even if five true full-range monitors are used during the production process. This is because acoustic summation in the studio space and electrical summation may well yield different results because acoustic summation and cancellation effects would have many other variables, not the least of which is the acoustic properties of the space, speaker placement, etc., that would result in a different sound than if all those signals were electrically summed together before reaching the loudspeakers. This is similar to reasons why studio engineers in days past would always sum their mixes in mono to check them, just to make sure.