here's my take on silencing a htpc case. It's made particularly difficult due to space constraints and airflow usually suffers. But it was a challenge, and it of course had to be silent to ensure a movie experience is not spoilt by noise.
With these issues in mind, I chose the following components:
Silverstone LC17 htpc case
Asus A8N-SLI Deluxe (chosen as it needed to be speedfan controllable and undervoltable). Modded with Zalman NB32K heatsink on the Nforce4 SLI northbridge.
Winchester 3000+ A64. Deep undervolt to 0.85Vcore idle@1GHz and 1.1Vcore max@ 1.8GHz using RMClock
Gigabyte 6600GT PCI-e passive video
1Gig of Kingston Value RAM
Seasonic S12 430W (version2 with Adda fan)
Samsung SP2004C 200G SATA (AAM enabled)
Pioneer 110d (surprisingly quieter than my NEC 3540)
Ok, let's get to it...
the Silverstone case:
The case needed to blend in with the rest of the AV equipment, and it looks like an amplifier. Importantly, it received the WAF (Wife Approval Factor) tick of acceptance due to its stealthed DVD, USB, firewire bays, and minimal bling LEDs and brushed aluminium fascia. From an spcr point-of-view, it has reasonable front and back air vents, and removable hdd cages with enough space to soft mount my HD.
The case stripped of its (loud) rear 2x80mm silverstone branded fans, the twin front 92mm metal cut-outs and HDD cages removed.
Assembling the parts:
2 types of foam is used, the white one is from the packaging of the case itself - a bubblewrap-like layered foam which I've never seen before but gleefully used. The black one is the mobo protector-type, both glued together. They form the foam supports for the HD.
The Zalman sits on a cardboard frame, and its stock fan removed.
Fanswapped Zalman 7000AlCu for a Nexus 92mm fan. The assembled CPU duct, seen from bottom.
The Samsung sitting on its foam feet, with elastic to prevent it toppling over during transport but isolating it from case resonant vibrations.
With 120mm Glacialtech fan and more foam. With the cardboard divider, this completely encloses the front (what I call the HD thermal zone), forces all fresh cool intake air around the HD before it enters the rest of the case.
bird's eye view, with CPU duct installed. The 120mm fan is aligned to blow onto the northbridge and one side of the GPU heatsink. All cables tied, tucked under the mobo, sleeved, or duct taped out of the way.
fibreglass flyscreen mesh, used to prevent bugs from crawling into the case but without impedement to airflow. Covers the twin 80mm CPU duct intakes, as well as the 3 empty slots directly in line with the 120mm fan - allowing the exit of hot air immediately out of the case.
I've placed the PCI cards such that it is staggered in height (high to low) from left to right: X-Mystique HDA sound card, then Dvico digital tuner card, then 802.11g wireless card. Between the 6600GT and the X-Mystique, a channel is formed for air to flow directly out via the back mesh. Also, the PSU fan sucks air over the top of the cards and exhausts that out too.
The Nexus and Glacialtech are speedfan controlled to 60-70% of max at idle, and the Seasonic takes care of itself. All run <800rpm, at idle with ambient of 25C I get temps of CPU 36C, Nbridge 41C, HD 33C, GPU 52C.
Silent? You bet - not audible even to my critical ears at 1m away.
Love to hear your comments, brickbats, suggestions