I don't know what the warranty is on the LSR-305's but it seems like 2 years electronics and 5 years for the speakers is the most common for subwoofers. My Focal Solo6 Be's are 3 and 5 years.
I am surprised KEF did not follow the convention of having a longer warranty on the drivers!
Notably, the $2500 MSRP LS50 Wireless model also only has a one year warranty, surely they didn't source their amps from some fly-by-night company!?