I have one of these masks for a few weeks and just started using it with a ResMed AutoSense 10 last Monday. I also use a chin strap with it, but don't know the manufacturer. The ResMed AutoSense was setup with a 15-18 cm pressure per the Dr's order. Previously I had been using a REMstar Pro M series with a max setting of 16 cm with this mask with no problems.
Here's my question. Occasionally during the night I get a whistling sound from the F&P ffm. At times it takes on the frequency change that sounds similar to today's police sirens, but at a much slower rate. If I rotate the mask part that attaches the hose I can make the sound go away, but am not sure that by itself solves the problem. I have a theory that it is more linked to my maximum pressure of 18 cm. According the SH I reach my maximum pressure randomly for short periods of time.
Otherwise my experience with the ResMed AutoSense 10 is very good.
Anyone have this experience? I am wondering if the mask is defective.
I used the F&P Zest nasal mask for a while. My pressure is 20 cm/H2O. I would get the whistling from the vents periodically. In my case, if I wiped the outside of the vent holes with my finger it would stop the whistling at least temporarily.
Someone else on this forum encountered the same type of problem and found that the vent holes had irregular diameters inside the plastic. The diameters looked OK from the outside. The reported problem was probably caused by either worn drill bits or a build-up on the cores in the die that formed the main part of the mask. Either way, it is poor manufacturing practice.
I could not think of any way to stop the problem that I had without changing the venting rate which I was concerned might have ramifications elsewhere in the operation of the CPAP. I currently use a Resmed FFM that never whistles.