Hardware Reference
In-Depth Information
because a valid comparison of output levels between different amplifiers can be difficult to
make. Because distortion increases with power output, amplifiers with higher THD
specifications will more easily have higher total or per-channel wattage ratings. Amplifiers
driving more speakers will have higher total wattage figures as well, even though the amount of
power to the primary stereo channels will usually be less. Finally, some manufacturers report
an inflated and relatively meaningless Peak Music Power Output (PMPO) figure, instead of the
Root Mean Square (RMS) figure standardized by the Federal Trade Commission. When making
wattage number comparisons, make sure they are RMS values reported at the same level of
THD; then, you can compare either the total wattage figures or the per-channel figures for the
primary front L and R (stereo) channels.
Before purchasing a speaker set, do your research and look at reviews of what others think about the
speakers you are considering.
You can control the volume and other sound attributes of your speakers in various ways, depending
on their complexity and cost. Typically, each speaker has a volume knob, although some share a
single volume control. If one speaker is farther away than the other, you might want to adjust the
volume accordingly. Many computer speakers include a dynamic bass boost (DBB) switch. This
button provides a more powerful bass and clearer treble, regardless of the volume setting. Other
speakers have separate bass and treble boost switches or a three-band equalizer to control low,
middle, and high frequencies. When you rely on your audio adapter's power rather than your
speakers' built-in amplifier, the volume and DBB controls have no effect. Your speakers are at the
mercy of the adapter's power.
For best audio quality, adjust the master volume on the sound card near the high end and use the
volume control on powered speakers to adjust the volume. Otherwise, your speakers try to amplify
any distortions coming from the low-power input from the PCaudio adapter.
A 1/8-inch stereo minijack connects from the audio adapter's output jack to one of the speakers. The
speaker then splits the signal and feeds through a separate cable from the first speaker to the second
one (often referred to as the
satellite speaker
).
Before purchasing a set of speakers, check that the cables between the speakers are long enough for
your computer setup. For example, a tower case sitting alongside your desk might require longer
speaker wires than a desktop computer.
Beware of speakers that have a tardy built-in sleep feature. Such speakers, which save electricity by
turning themselves off when they are not in use, might have the annoying habit of clipping the first part
of a sound after a period of inactivity.
Headphones can provide higher-quality sound for a given price than a comparably priced speaker set,
provide better listening to 3D audio special effects in games, provide privacy, and enable you to play
your PC audio as loud as you like. You can connect headphones via traditional audio jacks, or you
can buy USB-based versions.
For best results with newer sound cards that support four speakers or more, check the properties
sheet for the audio adapter and set whether you're using headphones, stereo speakers, or a larger
number of speakers. Use your audio software to set up 3D or other audio effects.
Make sure that speakers are placed properly. If you use a subwoofer, put it on the floor for better bass
sound and to reduce electromagnetic interference (EMI) with other devices.
If you still use a CRT, how can you tell whether wireless satellite speakers are causing interference
