A small piece of Melamine Foam was also placed on the top of the case as best we could. Since Antec rivet the top part of the SX1030B in place, it is difficult to get in there, but not totally impossible.

The bottom sheet of Melamine foam was positioned in much the same way after the little clips which hold the drive bay slides were removed.

Lastly, since the front fan intakes were not being used with a fan I positioned a small section of Melamine foam in the opening in the bezel to absorb some sound there. Rather than doing some complicated cutting for a piece of Melamine Foam on the inside of the case I simply cut a piece to fit between the bezel, and used some painters masking tape to hold it firmly in place.

The system we were testing this foam on is a Pentium 4 rig, and we did drop in a honeycomb PCI slot cover at the rear of the expansion bay to create an air intake area for the case. However, with only one case fan at rear being used, and one completely open fan port at the rear we were a little concerned about the fans stressing out, or straining to pull air in through the cracks. Ultimately though, the bottom honeycomb PCI expansion slot cover took care of the intake well enough as there were no sounds of straining fans when the case was closed up.

Installation is really straight forward, and the material easy to work with.

I could have added a lot more of the thin white foam to cover every square inch of exposed surface on the inside of the case but didn't. I was really only interested in placing it in the most accessible areas with large sheets so I could get a feel for the sound absorbency of the material.

The Test Environment

Before the Melamine sound absorbing material was added to the Antec SX1030B case some measurements were taken of the ambient sound levels in the room, and in close proximity to the case itself.

These results, which were obtained with an Omega HHSL-1 sound level meter (range 35dba-130dBa), are shown in the chart below, along with the results after the Melamine foam was installed. The sound meter was located approximately 8" away from the case for the front/side/rear noise measurements.

Case temperatures were recorded with an HH501DK digital thermometer by placing a Type-K thermocouple in the center of the case. The basic system thermal specs are as follows: Pentium 4 1.5GHz system, GeForce 3 Video card, (3x) 7200RPM hard drives, (2x) CD-ROM's, one PCI card and 431Watt Enermax power supply.

Melamine Foam Test Results
Measurement	Before	After
Ambient Sound Level:	47.4 dBa	40.6 dBa
Front of Case:	54.2 dBa	49.7 dBa
Side of Case:	53.3 dBa	47.5 dBa
Rear of Case:	58.5 dBa	56.1 dBa
Internal Case Temp.:	27.9 (C)	29.3 (C)
Ambient Temperature:	22.4 (C)

Keep in mind that a in most acoustic tests a drop of 3 dBa is hard to notice to the average human ear, but anything more should be easily perceptible.

As far as our little Antec case goes, the results are good, but not as significant as I had hoped to have seen. I'll probably try adding a few more pieces of Melamine foam, or perhaps another type of acoustic barrier to dampen the sound further in the near future.

For now, the ambient room sound level has dropped about 6 dBa, which is pretty good, and on closer inspection, the noise levels from the front and side of the case have been reduced by roughly 4-5 dBa. The sound levels vary slightly depending on how high up the case the meter is, so all measurements were made at the center line.

I didn't expect to see any reduction in the level of noise eminating from the rear of the case, so I was pleased with the 2 dBa drop, no matter how small it really may be. Case temperature rose only about 2 degrees (C), even though the front intake was blocked off by a piece of the sound absorbing material. I would guess that the dual fans in the Enermax power supply have a lot to do with keeping things cool inside the Antec case, and the extra intake we installed at the base of the expansion bay was sufficient.

I wasn't able to measure the noise frequencies before or after the modifications, but suffice to say, that with the decrease in noise level, the case is also less high pitched than it was previously. Some more modifications will be necessary to get the noise levels down further, but considering the cost of this Melamine Foam material, it does offer a quick way to experiment with what works, and what doesn't.

Update: After a few months of working with the system we were able to drop the noise levels down further by swapping out the AVC Sunflower heatsink in favour of a Zalman CNPS6500B-Cu cooler and pulling out the rear case exhaust fan entirely - remember though, the powersupply has two fans, one at rear and one just above the processor which aid in case exhaust. Noise levels are a few dBA lower, and the large 92mm fan used with the CNPS6500B-Cu heatsinks is pretty quiet on its own.

Other Resource and Articles you might also find interesting:
Frosty's Silent PC Project (samples of acoustic material types, low-noise product links, more soon)
FrostyTech Custom Cooling Projects

Computer Maintenance: Spiral Cable Wrap
Noisecontrol Magic Fleece Sound Absorbing Material
Cooling Fundamentals: Ball Vs. Sleeve Bearings
Cooling Fundamentals: Dusty Computers