No single best speaker here - they are built to different priorities, and the right one depends on your room, your sources and what you listen to.
| Area | Better | Why |
|---|
| Bass | B | Kanto YU6 digs deeper - 50Hz against 90Hz. |
| Built-in power | B | Kanto YU6 has the bigger amplifier (100W vs 50W RMS). |
| Connections | B | Kanto YU6 adds phono. |
| Size | depends | KEF EGG is easier to place; Kanto YU6 is bigger, which usually goes with fuller bass. Your room decides. |
| Cabinet | depends | Sealed vs Ported. Sealed is tighter and happier near a wall; ported digs lower but wants space behind it. |
| Expandability | depends | KEF EGG: a sub output; Kanto YU6: a sub output. |
| Price | evenly matched | Much the same money ($499 vs $540 a pair). |
A KEF EGG B Kanto YU6
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?
Kanto YU6 has the edge on paper, though the margin is not large. The rows marked "depends" may matter more to you than the score does. If a subwoofer is in your plans, the bass gap largely stops mattering - you would be crossing over above 90Hz anyway, so judge these on the other rows instead.
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.