Different kinds of product: one is active with its amplifier built in, the other passive and needs one. Judge them on how you want to own the system, not just the specs.
| Area | Better | Why |
|---|
| Bass | A | KEF LSX II LT digs deeper - 54Hz against 79Hz. |
| What you buy | depends | KEF LSX II LT is a complete system - just add a source. KEF LS50C Meta also needs an amplifier: more money and another box, but you choose it. |
| Connections | depends | KEF LSX II LT has Bluetooth, Wi-Fi, streaming and HDMI built in. With KEF LS50C Meta that all comes from the amplifier you pair it with. |
| Upgrade path | depends | KEF LS50C Meta can be re-amped later and outlive several amplifiers; KEF LSX II LT ages as one unit. |
| Size | depends | KEF LSX II LT is easier to place; KEF LS50C Meta is bigger, which usually goes with fuller bass. Your room decides. |
| Type | depends | A Powered Bookshelf against a Passive Center Channel - a different job rather than a better one. |
| Expandability | A | KEF LSX II LT: a sub output. |
| Price | evenly matched | Much the same money ($999 vs $900 a pair) - though the passive pair still needs an amplifier. |
A KEF LSX II LT B KEF LS50C Meta
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 LSX II LT suits you if you want one box, ready to play, with nothing else to buy. KEF LS50C Meta suits you if you already have an amplifier, want to choose the electronics, or expect to upgrade in stages. Neither is the better speaker in the abstract. If a subwoofer is in your plans, the bass gap largely stops mattering - you would be crossing over above 79Hz anyway, so judge these on the other rows instead. Match it to your room: we rate KEF LSX II LT the better fit for a mid-size room and a large room, and KEF LS50C Meta for near-field listening and a small room.
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.