I've replaced both rear bearings on mine, at different times (first car owner was a boatie) and yeah, it's a pretty obvious "wub wub wub" sound - just hard to determine where it's coming from!
I also have directional tyres that hum at certain speeds but it's a subtly different sound. Thought it might have been a failing CSB but that seems fine.
The second rear bearing I changed I wasn't 100% certain I was puling the correct bearing so I was VERY glad to see a galled race when I pulled it off/apart!
