Pro System One settings sync?

I have a Philips Respironics Pro System One. I got it through a distributor, but they are ridiculously expensive, so I am returning it. I ordered another online, for roughly 1/4 the price.

My question is this: I tried it out for the first time last night, and it made an odd whirring sound upon exhalation, that the machine from the distributor did not make. I am guessing that there is some setting that is different.

I have to return the one from the distributor tomorrow, and I think it makes sense to go into the doctor's settings on the machine from the distributor, and make sure that everything on the new machine is set up the same. I know that to modify the doctor settings I hold down both buttons for 5 seconds, but I am nonetheless daunted. Does anybody with some knowledge of the machine have any tips?

Thanks very much!!!

See if this helps

http://www.apneaboard.com/pr-system-one ... structions

Regarding the sound on exhale...sometimes it's just something really tiny...like the surface the machine is on... or the Flex setting for exhale relief ..or the filter placement or using one filter instead of two or vice versa.
Or the hose laying on the bed and some noise being conducted....or the change in force of your own exhale.
I can get quite a range of different sounds from my machine just by varying the force of my exhale.

And of course sometimes it's just a slight difference in machines it seems like even when everything else is exactly the same.

That link is fantastically useful thanks very much!