I have a CoolerMaster ATC aluminum case (I believe the exact model number is ATC-201 or similar to that). There is a "buzz" sound eminating from it, and unless the TV or music is on, it dominates all other background noise.
If you are familar with this case, it comes many fans, but I have turned most of them off. I have a CoolerMaster PS with a single 120mm fan always on low. I bought a Zalman heatsink fan combo (CU700) which runs on low to replace the Intel retail P4 unit. There is also an 80mm fan blowing out the back right below the PS (the only case fan I didn't disable).
I have two hard drives, both mounted in the front. One I left as is; the other I decided to try out the Zalman heat pipe cooler on. It has the rubber mounts to help dampen out the sound. I would estimate the hard drives to be in the 45-55db range.
After all of this, that annoying buzz is still there. At work we have some 1.5" think eggshell foam for sound proofing rooms. The cost of foam made and cut for computer cases is surprisingly high, so I took home a small sample and cut it up and placed it around the case to see if would make any difference before spending any more money..... but nope
I think the main problem is the aluminum case; the sound is reflecting and bouncing all over the place. For example, the new heat sink fan I installed is nearly silent when the case is open and I place my ear directly over it. However, as soon as I unplug all other devices, and close up the case, the fan becomes "louder". Is it a lost cause to try and quiet this system? My last resort would be buying a new case such as the Sonata. I haven't gotten a chance to research the case, but I know it is advertised as a "silent" case.
Thanks for any tips.