I've installed 14 GT AP-15s in my CaseLabs T10 case, and while they are relatively quiet, they have a bit of a higher pitch to their sound quality than I'm used to, and it's annoying me. (Compare this to this to see what I mean.
What can I do about this? I have them all on a fan controller, but it seems like they make this noise at all RPMs. Also, I've tried the rubber fan silencers and they do not make a difference. I was thinking about buying some AcoustiPack sound dampening material to place inside the case in hopes that it would take the edge off the noise. 8 of the fans are intake in the front of the case and 6 are exhaust on top of the case if that matters.
Thanks in advance!