These sit in different price classes - KEF LS50 Wireless II costs roughly 3.3x what SVS Prime Wireless Pro 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 | SVS Prime Wireless Pro digs deeper - 42Hz against 45Hz. A subwoofer would even that out. |
| Built-in power | B | KEF LS50 Wireless II has the bigger amplifier (380W vs 200W RMS). |
| Connections | evenly matched | The same set of inputs and streaming options. |
| Size | depends | SVS Prime Wireless Pro is easier to place; KEF LS50 Wireless II is bigger, which usually goes with fuller bass. Your room decides. |
| Expandability | depends | SVS Prime Wireless Pro: a sub output; KEF LS50 Wireless II: a sub output. |
| Price | A | SVS Prime Wireless Pro is cheaper - $899 against $2,999, about 70% less; arguably a different class. |
A SVS Prime Wireless Pro B KEF LS50 Wireless II
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?
Neither runs away with it - they trade advantages. Let the "depends" rows and your own room settle it. In a large or open-plan room, KEF LS50 Wireless II has the cabinet volume to fill it more easily; in a small room, near a wall or at desk distance, SVS Prime Wireless Pro is the easier speaker to get right. Think about the whole system, not just the speakers: the roughly $2,100 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.