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A Case and Power Supply for Your DIY Media PC

HTPC Case Logic

Here, we elaborate on the concepts and requirements for HTPC cases that were mentioned only briefly at the outset of this chapter. As we tackle these subjects head-on, we hope to teach you how to evaluate cases for yourself (or to look in published reviews for the rights kinds of information, should they be available). That’s because new cases hit the market all the time, and there’s a very good chance you’ll be considering cases that didn’t exist as we wrote this book.

Form Factor

When it comes to cases, the term form factor actually covers a multitude of meanings. In the most important sense, PC cases relate to those motherboard form factors they can accommodate. But the term can also be used to describe case orientation and layout, which allows us to distinguish towers by a vertical orientation, and horizontal or cube cases by a horizontal layout. Form factor can even be used as a metric of roominess, in that some cases qualify as compact or cramped, while others qualify as bigger and less crowded. That’s why we try to be clear about which meaning applies when we invoke this term in talking about HTPC cases.

It’s inarguable that a PC’s motherboard must fit into its case, so that aspect of form factor is something where parts must match up perfectly. The various ATX specifications are designed so that smaller variants of the same family (such as mini-ATX or micro-ATX) can be mounted in cases that support larger variants (full-scale ATX, in this scenario). But a case that accommodates only smaller variants won’t handle larger ones.

Your authors are somewhat split on the subject of form factor as it pertains to case orientation and layout. One of us believes that tower cases can be okay for HTPCs, providing they meet other criteria and don’t look too out of place in the living room. The other believes that only horizontal or cube cases make sense for entertainment center furniture. But happily both of us do agree that horizontal cases are probably the best choice for most HTPCs. Of course, one of the joys of building your own HTPC is that you can choose whatever type of case (or other components) that you like best.

Finally, when it comes to roominess, the laws of physics come into play. Smaller, more crowded cases invariably run hotter than larger, roomier cases even with identical components installed. That’s partly because smaller cases leave less space in which air can circulate, and partly because smaller cases build up and retain heat better than bigger ones do. It’s also true that installation and upgrades are easier in a roomier case because your hands and fingers have more room to maneuver as well. Mainly because smaller cases run hotter than larger ones, we urge you to go bigger rather than smaller when picking an HTPC case (or buying a pre-fab HTPC system for that matter).

Ventilation

When assessing a case’s ventilation, please pay close attention to the following factors:

  • The vented surface area should match the exhaust outlet surface area as closely as possible. That’s because ventilation works best when intake and exhaust are matched. Vents should also be positioned to help facilitate maximum airflow through the case. The Silverstone LC-04 you toured earlier in this chapter suffered somewhat from a ratio of vents to exhausts that favored vents, resulting in less than optimal case ventilation.
  • The internal layout of the case should be free of significant obstructions and should leave ample room for air to circulate and flow through following an effective cooling path across the heat-producing componentsthe CPU, video card, and hard drives. That’s a primary contributor to our earlier observation that a roomier case runs cooler than a more crowded one.
  • Fan mounts should be at least 80 x 80 mm (a more or less standard PC fan size), and provide at least 25 mm of vertical clearance. Larger 120 mm fans are preferable, because bigger fans can run more slowly yet move the same amount of air as smaller fans that run faster. Rotation speed contributes to noise, so slower is better when it comes to fans. Fans should also be placed to push or pull air over the hottest components (that’s why faster CPUs require dedicated fans and coolers).

The bottom line is that case ventilation is what keeps an HTPC as cool as possible. The cooler the HTPC, the less necessary it is to use fans to keep thing cool. If they must run, they can run more slowly and make less noise; if they don’t need to run at all, they make no noise. And of course, that leads directly into the next topic . . .

Noise Control

We begin this section by briefly reviewing why noise control is important for HTPCs. HTPCs are involved in producing sound, either by itself for music, or in tandem with images for TV or DVD playback. Both music and multimedia use sound dynamics for effect, so that sometimes things are deliberately quiet and other times things are deliberately loud. When things get quiet, nobody wants to hear a PC grinding, buzzing, or whirring away in the background, distracting viewers or listeners from their programming material. When it comes to an HTPC silent operation is the ideal, and as quiet as possible a very real goal that HTPC builders should seek to attain. This makes noise control a critical factor.

There are only a limited number of things one can do about noise, so while the prescription for quiet computing involves an astonishing amount of (and attention to) detail, only a few basic principles and practices are involved:

  • Use noise (or lack of noise) as an important selection criterion when picking components for an HTPC. Much of this book is devoted to this very topic in one way or another. The basic idea is to eliminate all unnecessary noise, and to limit all necessary noise to an affordable or practical minimum.
  • Make sure that what noise is produced must travel a long way to arrive at a listener’s ears. This explains why drives are at the front of most horizontal HTPC cases and exhaust fans blow out the back: sound must travel from the drives through the case, out the back, then around to the front and out the entertainment center to be heard. Hopefully, any noise will have diminished to nothing or near inaudibility by then.
  • Make sure that sources of noise are isolated from the case and the environment. The best HTPC cases (and modifications) drill out drive mount holes, so that rubber or silicon grommets may be inserted into those larger holes. This eliminates direct metal-to-metal contact between drive and case, and lowers the amount of vibration that can pass from one to the other.Companies like Antec (which also manufactures cases and power supplies) and Mitron offer a variety of interesting sound insulation products. Antec’s product line goes by the name of “Noise Killer,” consists of shaped silicon gaskets and washers, and includes offerings for 80 and 120 mm fans and PSUs.
  • Use sound insulation where and as it makes sense. For example, many system builders apply noise-dampening materials inside case panels for sound insulation. Although it’s commonly believed that foam damping can increase temperature levels inside your case, this is generally true only if you end up blocking airflow with the material, so proceed carefully. If a case sits on a shelf in a home entertainment center, it may work better to apply sound insulation only to the front half of a panel, rather than covering the whole thing. The back half is further away, so sound must travel further to your ears, and with drives typically front mounted, insulation near the source does the most good. Some cases are built with double walls because of noise insulation between inner and outer walls.

If you recognize potential sources of noise and take steps to prevent sound from propagating (by isolation or insulation) you’ll be able to reduce their impact on your listening experience as much as possible.

Materials and Construction

HTPC cases must also be built and designed to control noise. This affects the choice of building materials and the workmanship of the case. Though some experts argue that steel is preferable to aluminum for HTPC cases, aluminum’s lighter weight and greater ductility make it attractive to case builders. Most commercial HTPC case designs use an aluminum shell around a steel cage or steel drive bays and card cages.

As long as a case is sturdy, and tightly enough fitted to eliminate as much vibration or resonance in its outer panels as possible, it should do the job. For example, the Uneed case toured earlier in this chapter uses a heavy 8 mm aluminum front panel along with light 3 mm aluminum panels on the rest of the case (top, bottom, sides, and rear). It also incorporates two steel drive bay cages in the front of the case, and a steel expansion card and motherboard port block cage at the rear of the case. But because all mechanical connections between panels are tightly screwed together and fit extremely well, this case produces only a little vibration or resonant noise.

Some HTPC (and other) cases may come with sound dampening materials already installed, or offer extra-cost sound dampening kits (Uneed claims to offer such a kit for the x15e, but we can’t find any for sale). Other vendors such as Acousti Products offer aftermarket products like their AcoustiPack soundproofing materials that diligent HTPC users can install in their own PCs (be prepared to spend $50–100 to do the job right). Additional sound dampening is a good idea, provided you buy dense, high-quality materials (but keep them away from sources of intense heat like CPUs, GPUs, and Northbridge or Southbridge processors—or rather, away from their coolers or heat sinks).

Appearance

This is where aesthetics come into play, and that’s something that only a buyer can really appreciate in context. Make sure what you buy matches your other AV components (or at least doesn’t clash with them too much). But appearance is a characteristic you’ll want to consider when selecting any HTPC case for purchase. We found little or no difference between going with standard black or silver cases ourselves, probably because our AV setups already include a mix of black and silver elements. Those who’ve been more single-minded in their color schemes will want to pick an HTPC case that matches.

Te following table mentions numerous vendors who offer PC cases designed specifically for HTPC use. Of these, we’ve gotten good results with cases from Antec, Silverstone, and Uneed.

Name Type(s) Price Range URL/Remarks
AHANIX horizontal $180 to 280 www.ahanix.com; many models worth investigating; roomier cases make best choices, be sure to check vent/exhaust ratios.
Antec horizontal, tower, and cube $50 to 220 www.antec.com; P180 specially recommended.
Coolcases tower $100 to 200 www.coolcases.com; Chenbro PC-610 custom case recommended, company will also install fans and PSU for extra fee.
Thermaltake horizontal $100 and up www.thermaltake.com, numerous new offerings forthcoming, none reviewed yet.
Silverstone horizontal $110 to 220 www.silverstonetek.com; nearly all models worth investigating; roomier cases recommended.
Uneed horizontal $250 to 600 www.iuneed.com; touch screen models very pricey; all cases recommended.

 

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