Hi there…I currently have a Pioneer SX-770 receiver powering Kef K140 2 way speakers. I am planning to get a set of Kef Q4 3 way speakers. Could someone with more knowledge advise if it will be worthwhile changing and if my receiver has enough power for the Q4s? Thanks!!
Both speakers advertise similar sensitivity, so if you're happy with the volume you get out of the amp now, should be fine. I'd expect some bass falloff at higher volumes with either of those speakers, though.
The largest difference will likely come from getting the drivers up off the ground and closer to ear height. High frequency sounds fall off off-axis, so unless you do your listening on the floor, you should expect increased clarity from either the taller Q4s or by putting your current speakers on stands.
I built homemade speaker stands from a guide I found online. Parent is correct. Sound difference was shocking. Vibrations went into the air rather than floor. Consider isolating them with rubber stoppers to help reduce sending sound through them and keep it moving outward.
Adding to this, vertical directivity is often especially bad around the crossover regions due to phase shifts from crossovers. So speakers positioned higher or lower than the listener's ears would sound particularly bad. Elevating my floor standing speakers so that the drivers are at the typical ear height while listening dramatically changed the sound for the better.