Siblings in Klipsch's Reference Premiere (RP) II series, so they share a family sound. It comes down to size, output and price.
| Area | Better | Why |
|---|
| Bass | evenly matched | Much the same reach (60Hz vs 58Hz). |
| Amplifier needs | A | Klipsch RP-500C II is more sensitive (96dB vs 93dB), so it goes louder on the same amplifier. |
| Size | depends | Klipsch Reference Premiere RP 500SA II is easier to place; Klipsch RP-500C II is bigger, which usually goes with fuller bass. Your room decides. |
| Type | depends | A Passive Center Channel against a Passive Surround - a different job rather than a better one. |
| Price | evenly matched | Much the same money ($499 vs $450 a pair). |
A Klipsch RP-500C II B Klipsch Reference Premiere RP 500SA II
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?
Klipsch RP-500C II has the edge on paper, though the margin is not large. The rows marked "depends" may matter more to you than the score does. In a large or open-plan room, Klipsch RP-500C II has the cabinet volume to fill it more easily; in a small room, near a wall or at desk distance, Klipsch Reference Premiere RP 500SA II is the easier speaker to get right. If your amplifier is modest, vintage or valve-based, Klipsch RP-500C II is the safer partner - the other will want more current or more watts to sound its best.
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.