Articles and whitepapers

The Importance of Power Management for Home Theatre and Professional Audio/Video Equipment (1/12/2006)

By Garth Powell, Furman Sound

The advancements made in home theatre components and professional audio/visual equipment is astonishing. In the home, you can sit back and watch a DVD on your 42-inch plasma monitor, while the amplifier and woofer of your surround-sound audio system puts you right in the middle of the movie. Go to a bar or club and you can count on state-of-the-art systems that provide booming audio and stunning video displays to enhance your experience. But this technology comes with a high price tag. Whether they are for home or commercial applications, these components are an investment, and need to be treated as such with power management systems to ensure their longevity and peak performance.

The fact is that power coming out of electrical outlets is not 100 percent clean and stable. While some regions are worse than others, contamination is sure to be present in power sources the world over. The ultra-sensitive circuits in today's professional audio/visual equipment and home theatre components are technologically superb, but as they become more sophisticated, they also become more fragile. This has made it increasingly imperative to employ an advanced power management system, such as a power conditioner, for high-end home theatres and professional audio/visual systems.

A comprehensive power conditioner will filter out the AC noise present on the line, while at the same time protecting connected equipment from spikes and surges that are all too prevalent in today's power. According to the National Electrical Manufacturers Association (NEMA), a surge or transient is a brief overvoltage spike or disturbance on a power waveform that can vary in intensity from just a few volts to extremes of tens of thousands of volts. These disturbances are not as rare as one may think, and can damage, degrade, and even destroy electronics within a home or commercial building.

NEMA cites three types of effects that transients have on electronic equipment: disruptive, dissipative, and destructive. Disruptive effects are usually encountered when a transient enters the equipment by inductive coupling, where a magnetic field - created by electric current flows - extends to a second wire and induces a voltage. This leads to equipment malfunction as electronic components try to process the transient as a valid logic command. Dissipative effects are associated with repeated stresses to IC components. The materials used to fabricate ICs can only withstand a certain number of repeated energy level surges. Destructive effects include all conditions where transients with high levels of energy cause equipment to fail instantaneously. Most often there is visible physical damage like burnt or melted electronic components.

There is not a power utility in the world that can guarantee pure, clean electricity free of transients or AC noise. This is due in part to the fact that much of the noise and transients are created within the very building using the power. Indeed NEMA research indicates that 60% to 80% of surges are created within the facility itself! Where do these surges originate? Most commonly, they are a result of the switching power supplies located in countless common devices, from personal computers to simple thermostats. This is why power protection devices that protect the whole house or whole facility are not as effective as conditioners directly connected to your sensitive components. Unless the building housing the components is completely devoid of electronics with switching power supplies - which is not very likely - it is important to invest in a power conditioner.

In addition to protection against surges and spikes, another important feature of a power conditioner is filtering, which is critical as it keeps sensitive electronic equipment performing optimally and eliminates AC noise. Noise affects virtually every element involved in a high-end audio or visual environment, and it ends up masking much of the detail needed for the best possible sound definition in audio and resolution in video.

Because of this noise, AC power must be properly filtered. Filtering means taking the noise present on an AC line and lowering it in level to such a dramatic degree, and over such a wide range of frequencies, that it cannot contaminate a signal being captured or reproduced. This is why AC noise filtering is so vital for today's sensitive and critical electronic components.

Signal with noise prior to filtering (a), and signal after being filtered with Furman Linear Filtering Technology (b)

Not all filters, however, are created equal. The majority of products on the market either do not provide filtering or have antiquated designs that have not been linearized. Linear Filtering Technology(tm) (LiFT) is a special technology featured in Furman Sound products that assures that under any load condition, and regardless of the AC socket provided, the filter will operate over the widest range of frequencies and, more importantly, as evenly and consistently as possible. This provides crisp, clear sound from audio systems and intense visual displays. In addition, Furman products offer Series Multi-Stage Protection (SMP) to clamp and dissipate damaging transient voltages without sacrificing any internal components, and Extreme Voltage Shutdown (EVS) to protect against accidental connections to 208 or 240VAC.

Furman's Elite-16 PF E advance technology is specifically designed to protect sensitive electronic equipment

The price of not having power protection can be high. A single power conditioner costs about USD200 on average, but that one conditioner is probably powering several thousand dollars worth of equipment. In the event of something catastrophic, such as a lightning strike, the conditioner protects everything that runs on it. And remember, with the aged city power grids, surges and failures of all types can be expected. The cost of not having a power conditioner is even higher in commercial systems, where there is not only the cost of the ruined equipment, but also the cost of replacing it, including the labour cost, and a loss of business until the replacement is in place.

Furman would like to acknowledge the NEMA Surge Protection Institute, which was a major resource for this article.

Garth Powell is the Senior Product Designer for Furman Sound USA. Furman Sound has been designing, developing, and manufacturing professional electronic products since 1974, and is a world leader in the AC power management market.

www.FurmanSound.com