Different kinds of product: one is active with its amplifier built in, the other passive and needs one. Judge them on how you want to own the system, not just the specs.
| Area | Better | Why |
|---|
| Bass | B | Klipsch RP-500M digs deeper - 48Hz against 55Hz. A subwoofer would even that out. |
| What you buy | depends | Klipsch R50 PM is a complete system - just add a source. Klipsch RP-500M also needs an amplifier: more money and another box, but you choose it. |
| Connections | depends | With Klipsch RP-500M that all comes from the amplifier you pair it with. |
| Upgrade path | depends | Klipsch RP-500M can be re-amped later and outlive several amplifiers; Klipsch R50 PM ages as one unit. |
| Size | depends | Klipsch RP-500M is easier to place; Klipsch R50 PM is bigger, which usually goes with fuller bass. Your room decides. |
| Price | A | Klipsch R50 PM is cheaper - $450 against $579, about 22% less. And that is the whole system. |
A Klipsch R50 PM B Klipsch RP-500M
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 R50 PM suits you if you want one box, ready to play, with nothing else to buy. Klipsch RP-500M suits you if you already have an amplifier, want to choose the electronics, or expect to upgrade in stages. Neither is the better speaker in the abstract. If a subwoofer is in your plans, the bass gap largely stops mattering - you would be crossing over above 55Hz anyway, which makes the cheaper Klipsch R50 PM much easier to justify. In a large or open-plan room, Klipsch R50 PM has the cabinet volume to fill it more easily; in a small room, near a wall or at desk distance, Klipsch RP-500M is the easier speaker to get right.
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.