Q: What is power conditioning and why do I need it?

Most of us just want to plug in our high-performance A/V gear and flat panel TV and let 'em rip. But if it's optimum performance you're after, you should give your system some higher-octane fuel. Power-conditioning devices will clean the electricity entering your home, protect your equipment, and in many cases serve up an uninterruptible electrical supply to your precious A/V gear. For the gospel on power conditioning, Bob Smith of Panamax and Garth Powell of Furman Sound share an introduction on the subject with five things consumers should know.

1. The price of not having power protection can be high. A premium power conditioner can range from $400 to $3,500, and the more costly and complex the home theater system, the more power management equipment it likely needs. However, these AC management products are typically powering several thousand dollars worth of equipment. Remember: It's not just about protecting your gear from catastrophic events such as lightning strikes. AC power is the lifeblood of your system, and with today's ultra noisy, aged power grids, your theater's performance relies on pristine power. Don't gamble with a mere outlet strip.
2. Whether it's a flat-screen panel or a projector, your video display is the home theater centerpiece. But remember that the larger the screen, the more noticeable the artifacts and deficiencies in the picture. Common video distortions such as image pixilation, blurred images, lack of contrast and loss of detail greatly diminish the viewing experience. A major source of these deficiencies is AC line noise. To ensure a stunning picture and sound with increased audio and video detail, bold colors, and vibrant sound stage, eliminating the AC noise is a must, and that's where appropriate power conditioning and filtering can help.
   
   "Filtering" means taking the noise on an AC line and lowering it over a wide range of frequencies so it cannot contaminate signals. Many AC power products either don't provide sufficient filtering, they or have antiquated circuit designs. To eliminate the fullest spectrum of noise and ground noise, technologies incorporating isolation transformers, balanced power output and outlet isolation are recommended.
3. Many home theater power amplifiers are designed to deliver the vast increase in power for today's digital audio content. However, when the fast dynamic peaks occur, the power supply is typically taxed or stunned for a brief time. Amps pull tremendous current from the wall outlet to stabilize themselves. If this transfer of energy is slow, inefficient or impeded, current compression becomes a technological bottleneck. Most surge protectors can actually exacerbate this problem by raising the AC impedance, further depriving amplifiers of the current replenishment they need.
   
   One solution is found in AC power conditioners offering engineered "high current" outlets that minimize impedance for power amplifiers and powered subwoofers. A better solution for very demanding amps and powered subs is to incorporate a power conditioner that provides a momentary current reservoir that lowers the AC impedance. This ensures that the amplifier's power supply gets the current it must have on demand, regardless of volume or content.
4. Voltage irregularities can cause sensitive electronics equipment to malfunction and can lead to severe damage. To prevent this, a voltage regulator accepts a wide range of AC voltage and then transforms it to a safe, stable voltage that is delivered to the connected equipment. In the United States and Canada, all home theaters must have AC protection and purification, but AC voltage regulation is only necessary in extreme circumstances. NEMA (National Electrical Manufacturers Association) standards require electronic gear to operate at design specifications within 5 percent of 120 volts. A problem arises because utility companies are allowed to deliver power to a residence within 10 percent of 120 volts, and more than a third of electronic system installations in North America receive AC voltage outside of that 5-percent range. For these, regulation is a huge advantage. It's best to find a regulator that utilizes quiet active electronic circuitry and that can handle the high-current demands of a full home theater.
5. There isn't a power utility in the world that can guarantee pure, clean electricity that's free of transients or AC noise. This is partly because 60 to 80 percent of surges are created within the home itself. While most of these surges are modest, over time they can have a severe detrimental impact on your electronics. Surges typically result from switching power supplies located in countless common devices, such as appliances with AC motors like heating and cooling systems, a washer or dryer, personal computers and simple thermostats. Since these surges will backfeed from AC outlet to outlet, they bypass the home's main transformer and any surge protection connected at the service entry. Therefore, "whole-house protection" is not as effective as power conditioners that are directly connected to your sensitive home-theater components.