For example, in electronics, speed is largely a function of capacitor discharge rates, voltage swings and part counts. In speakers, speed is largely a function of efficiency, mass, and flux density. In the 12 inch woofer we may have a moving mass of 85 grams. Without understanding anything else about the dozens of variables that effect this, simple physics dictates that the lighter something is, the faster it can change directions and move. Electronics are far more complex from a speed standpoint, but equally as important.
Reason being the electronics and speakers can now reveal the shortcomings of the source.
In the same system, a slow preamp is installed in place of the fast one. Now the grainy top end is gone, the digital sound seems smoother more analogue and the end result is pleasing non-fatiquing sound. The reason being the preamp has masked the shortcomings of the source. Masking, or altering the sound is often the side effect of complex circuits that use lots of parts. The less parts in the signal path, the faster the circuit typically becomes.