Re: Pumps...

[Keith Brummett <brummett at ds_net>]

     Adam Shaw wrote:
     > 
     > Anyone out there own, or has owned, a Rainbow Lifegard Little
     > Giant Q series pump (model 3MDQX-SC), and would like to testify
     > to the level of noise it outputs?

     I use a 2MDQ-SC.  The direct noise is a quiet hum and some airflow
     noise coming from the ventilation slots.  Both are masked by the
     various gurgling noises of the trickle filter, and all is
     contained by the cabinet I use.  However, the pump needs to be
     isolated with respect to physical coupling with the cabinet.  It
     vibrates such that the cabinet, sump tank, and other equipment act
     as soundboards, and the resulting noise is orders of magnitude
     greater than the direct noise.  Right now, I have the pump sitting
     on layers of cloth and foam, and that works OK.  There are still a
     few instances, when the cabinet doors are open just so, that I
     get a buzzing sound.  Somewhere on my "list of things to do" is
     to bolt the pump to a small piece of thick plywood, and suspend
     the whole assembly within the cabinet via rubber cords. (Or, maybe
     go the other way, and silicone the pump to a concrete block; I'll
     have to pull out the old textbooks and review physical high-pass
     and low-pass filters.)

     Of course, this could all be a manifestation of some particular
     oddity about my specific cabinet and set-up, so maybe you won't
     have the issue.  Still, a good return policy by the vendor of
     your pump would be handy, just in case.

     -- Keith

-- 
    W. Keith Brummett                   "There are 10 kinds of people
    brummett at ds_net                     -- those who understand binary
    http://www.ds.net/~brummett         and those who don't."