Can a Quality Full Range Speaker be the Limiting Component in a system?

Well, certainly, if the speakers match the room poorly. (I am assuming, for purposes of your question that the “quality speakers” are not dynamically limited, are capable of undistorted low bass to 30 Hz and have a treble response to 20 kHz.) Every residential room has room gain in the Bass between 40 and 50 Hz. The trick is to have the room gain complement the speaker’s anechoic bass roll-off the achieve flat response in the room. To some extent, these problems can be ameliorated by placement (in or any from corners), and of course there’s always active equalization. There is no one universal solution that the speaker builder can design for, because rooms are different. Likewise, at the top end, a flat treble power response will sound unbelievably bright in all but the most heavily damped rooms (heavy drapes, thick carpets, lots of upholstered furniture). Again, because rooms vary in reflectivity, there’s no single perfect solution that the speaker designer can employ that will work everywhere.As with bass, there are possible adjustments to the room that can make the speaker “fit,” but that begs the question as to which is subordinate, the room as its decorated, or the speaker. If we listened to stero outside in an anechoic environment, then this would be simple. However, since we listen to speakers in rooms of varying characteristics (not just size and shape), a quality speaker in the wrong room can be a limiting factor in system performance.