RM, you asked about floor standing speakers and the why of them. I really didn’t answer your question so this.

First, nomenclature: while we say ‘speaker’ referring to the speaker box what the boxes contain are more properly called ‘transducers’ (able to convert an electrical signal to mechanical motion). Your system doesn’t really have 7.1 speakers but 15 ‘transducers’.

If we ask a single speaker to handle say 40-20,000 Hz the sound is garbled: high and low frequencies intermesh and neither is clear. So we divide the incoming signal into two with the highs separated to a smaller speaker and the lows to the larger. That’s a typical bookshelf speaker: one high frequency transducer and one low.

So since a transducer works best with a limited frequency range, a floor-standing speaker with say three larger and one smaller transducers sends the highs to the smaller and divides the lower frequencies so each of the three larger transducers are given a separated signal: one may be 100-700, the other 700-1300, and the last 1300 to where the tweeter takes over – which could be 1800-20,000.

The sub has one speaker because it is assigned 30-150 Hz.

So the essentials of a floor-standing speaker is just that said above. What makes a difference in floor-standing speakers is the quality of the transducers, the efficiency of the crossover electronics, and cabinet construction. Your center speaker is a good example of better construction and internal crossover.

MichaelR