On Mon, 03 Oct 2005 09:20:08 -0700, Glenn Gundlach wrote:


John - kd5yi wrote:
"Terry Pinnell" wrote in message
...
Michael Gray wrote:

It is usually the sides of the case behaving like a drum.
Try damping both sides with your hands, and see what happens.

That makes sense, but holding both sides doesn't diminish the beat. I
can now *feel* it as well as hear it (~ 1 Hz). Any other ideas on
stopping it? How about that rpm reduction I mentioned?

--
Terry Pinnell
Hobbyist, West Sussex, UK



You are an exceptional person to be able to hear 1 Hz!

John

Not at all, you can do it too. The beat he's hearing is the same as
tuning a musical instrument. My question is: how accurate is the '7200'
RPM? Would different models be phase locked or are they just 'close'?
AND, is it a balance issue with the drives (or fans)?

Well, drives shouldn't whine so much that they beat against each other's
whine (there's gotta be a joke in that sentence somewhere - anyone?) -
take the noisy drive back to the store, and get one that isn't eating
its own bearings.

Good Luck!
Rich