It needs to be more capable than the L/R for this to work well, unless all 3 are significantly oversized to begin with. The L/R play far less than the center does.
Playing
less should not be confused with playing
less often.
While it's true the center channel often handles a huge amount of a given soundtrack, that absolutely does NOT mean that the sounds it is playing are particularly taxing to play in terms of volume and/or dynamic range or frequency bandwidth needed.
In other words, how does some guys talking up a storm in Oppenheimer for half the movie compare to the atom bomb going off in terms of taxing available resources?
What should matter in upper bass terms is whether the speaker is in a good position to support corrections for issues found in the system.
For example, just experimenting with double bass turned on in a given system I was playing with that had three full range mains (L/C/R) and only one sub for one row of seats with the only significant problem Audyssey couldn't solve being a 12+dB valley mode at the MLP at 55Hz and running REW tests, it's clear that having the left main near a single used dub play a tone, it doesn't help a thing.
But having the full range center channel playing at -3dB relative to bass (meaning the sub was increased by 3dB hot and thus making it impossible to create a significant peak, only to fill in nulls), almost completely eliminates that 12dB null at 55Hz. The right speaker had little more effect than the left main. The surrounds were crossed at 80Hz and fell off around 60Hz so no help there.
So what would ART do with this system? Tell you to go buy one or two more subs? Or does that little test show it could solve the 55Hz mode using the center speaker? Is dialog taxing that speaker at 55Hz that can't be used? Is a complex waveform necessarily more difficult to reproduce than a simple one? A simple square wave can destroy a woofer, for example....
