Audio Hardware - Upgrading and Repairing PCs - page 699

A good way to solve problems of all types with PnP cards and integrated hardware, a PnP BIOS, and
Windows is to use the Device Manager to remove the sound card or integrated audio, restart the
system, and allow the card's components to be redetected. This installs a “fresh” copy of the software
and reinserts Registry entries.
If reinstalling the current driver with this method doesn't improve your results, download and install
updated drivers for your sound card or integrated audio.
Speakers
Successful business presentations, multimedia applications, and MIDI work demand external high-
fidelity stereo or surround speakers. Although you can use standard stereo speakers, they are often too
big to fit on or near your desk. Smaller bookshelf speakers are better.
Sound cards offer little or none of the amplification needed to drive external speakers. Make sure you
use speakers made for PCs, or connect your sound card or integrated audio to a home theater system's
amplifier, which can provide the power needed to run standard speakers.
Caution
Although most computer speakers are magnetically shielded, do not leave recorded tapes,
watches, credit cards, or other devices with magnetic recording surfaces in front of the
speakers for long periods of time.
Quality sound depends on quality speakers; an inexpensive speaker makes any type of PC audio sound
tinny.
Speaker Selection Criteria
Dozens of models of PC speakers are on the market, ranging from inexpensive minispeakers from
Sony, Creative, and Logitech to larger self-powered models from prestigious audio companies such
as Bose, Klipsch, and Altec Lansing. Almost all speakers, even in the under $30 range, include
subwoofers to provide additional bass response. To evaluate speakers, it helps to know the jargon.
Speakers are measured by three criteria:
• Frequency response —A measurement of the range of high and low sounds a speaker can
reproduce. The ideal range is 20Hz-20KHz, the range of human hearing. No speaker system
reproduces this range perfectly. In fact, few people hear sounds above 18KHz. An exceptional
speaker might cover a range of 30Hz-23,000Hz, and lesser models might cover only 100Hz-
20,000Hz. Frequency response is the most deceptive specification because identically rated
speakers can sound completely different.
• Total harmonic distortion (THD) —An expression of the amount of distortion or noise created
by amplifying the signal. Simply put, distortion is the difference between the sound sent to the
speaker and the sound you hear. The amount of distortion is measured in percentages. An
acceptable level of distortion is less than 0.1% (one-tenth of 1 percent). For high-quality audio
equipment, a common standard is 0.05%, but the cheap amplifiers included with many
inexpensive speakers have a distortion of 1% or more, which is at least 20 times greater.
• Watts —Usually stated as either total watts or watts per channel, this is the amount of
amplification available to drive the speakers. This is one of the more misleading specifications