These sit in different price classes - KEF Coda W costs roughly 1.7x what Klipsch R-51PM does. Expect it to lead on paper; the question is whether the gap is audible enough in your room to be worth it.
| Area | Better | Why |
|---|
| Bass | A | KEF Coda W digs deeper - 41Hz against 68Hz. |
| Built-in power | evenly matched | Similar onboard amplification (100W vs 120W RMS). |
| Connections | depends | KEF Coda W adds HDMI; Klipsch R-51PM adds phono. |
| Size | depends | Similar cabinet size - neither is easier to fit. |
| Expandability | depends | KEF Coda W: a sub output; Klipsch R-51PM: a sub output. |
| Price | B | Klipsch R-51PM is cheaper - $599 against $999, about 40% less; arguably a different class. |
A KEF Coda W B Klipsch R-51PM
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?
KEF Coda W is ahead, but only on 1 of the measured areas, and it costs about 67% more. That is a lot of money for a narrow margin on paper - Klipsch R-51PM looks like the sensible buy unless something else about the KEF Coda W appeals to you. If a subwoofer is in your plans, the bass gap largely stops mattering - you would be crossing over above 68Hz anyway, which makes the cheaper Klipsch R-51PM much easier to justify. Think about the whole system, not just the speakers: the roughly $400 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.