Beam Serenity Plus doesn't ****

Question

We have a Beam Serenity Plus whole house vacuum. My wife emptied the basket this afternoon and I've cleaned the filter. Since replacing the basket, the vacuum still makes the same amount of noise that it made prior to cleaning--comparable to standing right next to a relatively quiet jet engine--but the vacuum doesn't have much sucking power. Near as I can tell, there is nothing stuck in the hose or in the pipes. Any suggestions? Thanks,Mike