Cooler Master is known for overrating their fans. Don't trust their specs, check out third party reviews. Noctua, Delta, Panasonic (Panaflo) are a couple companies known to publish accurait numbers. Here's an example
Actually I'm pretty interested in why the noise-blocker died. They're pretty reliable fans. *shrug*
At any rate, OP, give us some more info to work with!
the fan just start making clicking noise and it died one day. note that they are mounted horizontal in a Raven Rv02-E case.
The Excalibur won't make any clicking noises being mount horizontal will it...?