These sit in different price classes - Kanto YU6 costs roughly 1.8x what Jamo S 801 PM 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 | Kanto YU6 digs deeper - 50Hz against 76Hz. |
| Built-in power | A | Kanto YU6 has the bigger amplifier (100W vs 50W RMS). |
| Connections | A | Kanto YU6 adds phono. |
| Size | depends | Similar cabinet size - neither is easier to fit. |
| Expandability | depends | Kanto YU6: a sub output; Jamo S 801 PM: a sub output. Jamo S 801 PM sits in a wider range (7 models), so a matched surround system is easier later. |
| Price | B | Jamo S 801 PM is cheaper - $300 against $540, about 44% less; arguably a different class. |
A Kanto YU6 B Jamo S 801 PM
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?
The usual trade-off: Kanto YU6 measures better, Jamo S 801 PM costs about about 80% more% less. Whether that gap is worth the money is the call only you can make - and in a normal room it is often smaller than the numbers suggest. If a subwoofer is in your plans, the bass gap largely stops mattering - you would be crossing over above 76Hz anyway, which makes the cheaper Jamo S 801 PM much easier to justify. Think about the whole system, not just the speakers: the roughly $240 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.