A generation apart: JBL 4305P is the newer design, against a 2016 model. Newer is not automatically better, but the older one is more likely to be discounted or near run-out.
| Area | Better | Why |
|---|
| Bass | A | JBL 4305P digs deeper - 45Hz against 79Hz. |
| Built-in power | A | JBL 4305P has the bigger amplifier (300W vs 230W RMS). |
| Connections | evenly matched | The same set of inputs and streaming options. |
| Size | depends | JBL 4305P is easier to place; KEF LS50 Wireless is bigger, which usually goes with fuller bass. Your room decides. |
| Expandability | depends | JBL 4305P: a sub output; KEF LS50 Wireless: a sub output. |
| Price | evenly matched | Much the same money ($2,200 vs $2,200 a pair). |
A JBL 4305P B KEF LS50 Wireless
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?
JBL 4305P 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 79Hz 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.