If you want the best picture and sound quality from your HDTV and all of your other home entertainment equipment, then consistent clean
power is essential. Unfortunately, the AC (alternating current) power coming from your wall outlet is neither clean nor consistent. In
an ideal situation, the graph of the waveform of an AC power circuit is a smooth sine wave; graph what is coming from your outlet and it is
not so smooth. The reality of our current situation is that we are living in an age of advanced technological innovation, with everything
becoming dependant on sensitive computerized equipment. Unfortunately, the transmission and distribution of the power needed to run all of
this sensitive equipment has not evolved in the same manner or pace. Our current power grids were designed to supply the needs of
manufacturing factories and their big machines, not your ultra sensitive Plasma HDTV. The AC power that comes into your home is filled
with two things you don’t want; electromagnetic interference (EMI) and inconsistent voltage.
Electromagnetic interference (EMI) will limit and degrade the performance of your AV equipment. EMI is sometimes mistakenly referred to
as Radio Frequency Interference (RFI); RFI is actually a particular type of EMI. You have probably witnessed EMI first hand and didn’t
know it (ever seen momentary snow in your TV picture when the compressor from the refrigerator starts or someone turns on a hair dryer?).
EMI is caused by electromagnetic radiation emitted from a source external to an electrical circuit. The list of possible external sources
is lengthy as it can come from anything that has rapidly changing current, even natural things like the northern lights and the sun.
There are two types of EMI; narrowband interference, (radio and TV stations, cell phones, cell phone towers, etc.), and broadband interference
(power transmission lines, electric motors, bug zappers, etc.), basically anything with an electrical circuit is a potential source.
EMI causes video noise (snow or static) in the picture, and reduces both color purity and contrast levels. In audio, EMI is heard as a
hum or buzzing sound. EMI can be reduced by using filtering and isolation circuitry to isolate noise before power is fed to your components.
The use of power bars with EMI filtering and isolation circuitry between the wall outlet and your AV equipment will go a long way to improving
their performance; the more filtering and isolation across your system, the better. The $6 hardware store power bar, which is designed to
provide you with minimal spike and perhaps lightening protection, is just not appropriate. At minimum, purchase a power bar with EMI
filtering. One with EMI filtering and isolation circuitry is a better purchase.
Another performance robber is the inconsistent voltage that comes from your wall outlet. Your AV components’ power supply is designed to
operate with a particular input voltage (usually 120 volts); it then transforms that power in tiny electrical pulses, to turn on and off
millions of individual pixels in the case of an LCD display panel. It is not uncommon the see the voltage from your wall outlet having a
momentary drop (commonly called a “sag”) to as low as 80 volts and rise to 130 volts (a “surge”). The voltage fluctuations put stress on your
equipment’s power supply, not allowing it to perform optimally (imagine an artist trying to paint a masterpiece on a moving bus, as it travels
across a bumpy road). With response time measured in milliseconds (1 millionth of a second), the power supply circuitry has to make
unpredictable adjustments before it sends tiny electrical impulses to individual cells of the LCD or Plasma panel.
To combat voltage irregularities, you can use devices commonly referred to as Power Conditioners. Power conditioners will employ a voltage
regulator (or stabilizer) to maintain a constant AC output, by producing a higher output voltage when the input voltage drops too low, and a lower
voltage when the input is too high. Some advanced Power Conditioners will also employ a battery backup system, for use when the power drops below
a tolerable threshold.
Power equipment that can combat the effects of EMI and inconsistent voltage will cost as little as $60, for basic EMI filtering, to as much as
$1500 for multi-stage EMI filtering and voltage regulation.