A generation apart: Klipsch R-51PM is the newer design, against a 2014 model. Newer is not automatically better, but the older one is more likely to be discounted or near run-out.
| Area | Better | Why |
|---|
| Bass | A | Klipsch R-51PM digs deeper - 68Hz against 90Hz. |
| Built-in power | A | Klipsch R-51PM has the bigger amplifier (120W vs 50W RMS). |
| Connections | A | Klipsch R-51PM adds phono. |
| Size | depends | KEF EGG is easier to place; Klipsch R-51PM is bigger, which usually goes with fuller bass. Your room decides. |
| Cabinet | depends | Ported vs Sealed. Sealed is tighter and happier near a wall; ported digs lower but wants space behind it. |
| Expandability | depends | Klipsch R-51PM: a sub output; KEF EGG: a sub output. |
| Price | B | KEF EGG is cheaper - $499 against $599, about 17% less. |
A Klipsch R-51PM B KEF EGG
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 R-51PM leads across most of the measured areas for a fairly modest premium, which makes it the easier pick if the budget stretches. KEF EGG is the one to take if it does not. If a subwoofer is in your plans, the bass gap largely stops mattering - you would be crossing over above 90Hz anyway, which makes the cheaper KEF EGG much easier to justify. In a large or open-plan room, Klipsch R-51PM has the cabinet volume to fill it more easily; in a small room, near a wall or at desk distance, KEF EGG 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.