I find the generic filters do not quite fit right. The generics do feel "different." And, the generics frustrate me by falling out while I'm trying snap in the cover. So, I will not accept anything but ResMed's filters. With brand name filters I push the filter into the cover at the left/right edges; and it stays in place while I snap the cover in place.
Yes, I think there is a design weakness in the S9 filter cover. There does appear to be a path around the edge for "dirty" air to get past.
I doubt the bit of bypass "dirt" hurts the motor. I believe the bearings are sealed.
I can hear my blower motor speed up and slow with each breath; and I'm near deaf in one ear.
INFORMATION ON APNEA BOARD FORUMS OR ON APNEABOARD.COM SHOULD NOT BE CONSIDERED AS MEDICAL ADVICE. ALWAYS SEEK THE ADVICE OF A PHYSICIAN BEFORE SEEKING TREATMENT FOR MEDICAL CONDITIONS, INCLUDING SLEEP APNEA. INFORMATION POSTED ON THE APNEA BOARD WEB SITE AND FORUMS ARE PERSONAL OPINION ONLY AND NOT NECESSARILY A STATEMENT OF FACT.
I've only ordered oem filters off the web, but honestly have never checked for dust around the edges. I guess I have homework tonight now.