Both are Klipsch, from different ranges - so the house sound is shared and the differences are mostly in scale, engineering and price.
| Area | Better | Why |
|---|
| Amplifier needs | evenly matched | Similar sensitivity (93dB vs 93dB) - both want much the same power. |
| Size | depends | Similar cabinet size - neither is easier to fit. |
| Cabinet | depends | Ported vs Sealed. Sealed is tighter and happier near a wall; ported digs lower but wants space behind it. |
| Expandability | depends | Neither adds bi-amping, a sub output or height drivers. Klipsch Reference Premiere RP 500SA sits in a wider range (17 models), so a matched surround system is easier later. |
| Price | B | Klipsch Reference Premiere RP 500SA is cheaper - $299 against $450, about 34% less. |
A Klipsch Reference Premiere RP 500SA II B Klipsch Reference Premiere RP 500SA
depends neither is better in the abstract - it turns on your room, your system or how you will use them. Only specs published for both speakers are judged; anything missing on either side is left out rather than guessed.
Which should you choose?
Neither runs away with it - they trade advantages. Let the "depends" rows and your own room settle it. Think about the whole system, not just the speakers: the roughly $151 saved by taking the cheaper pair would buy a subwoofer or a better amplifier, and either usually does more for the sound than the difference between these two.
And remember what a spec sheet cannot show: how each looks in your room and whether the finish suits it, what dealer support and warranty are like where you live, and how they actually sound to you. If you can hear them first - ideally with your own music - that will tell you more than any number above.