Simple Answer: Turn the music up louder!
No but seriously, if you need that fan in there, find a different way to mount in on there. I'll show you what I did with my HDD fan!
***NOTE*** The HDD fans is the multicolored one!
As you can see, the HDD fans are actually suppossed to be underneath the HDDs, but they don't fit, so the slots on the side of the HDD, I just took some zip-ties and zip tied the sucker in there. They actually look really good right there and happen to cool the PC enviorment more then they would have if they were underneath the HDDs. Plus the cool the HDDs a good amount too!