PC Hardware Annoyances

SPEAKER ANNOYANCES

MANAGING SPEAKER HUM

The Annoyance:

Why does so much hum and buzz come from my speakers?

The Fix:

Symptoms like hum and buzz indicate a power grounding issue, but start with the basics (e.g., checking for tight speaker connections). Remember that high volumes on your amplified speakers can really bring out any unwanted noise in your audio, so turn up the mixer signals in the Windows Volume Control, and turn down the speaker volume to the lowest acceptable level (see "Eliminating Audio Distortion" earlier in this chapter). This minor adjustment often goes a long way toward cleaning up a noisy signal. Of course, there may be damage to the speaker’s amplifier circuit, so try another set of powered speakers.

Also, check for low-frequency noise on the AC power line. For example, high-energy devices such as air conditioners, motors, coffee makers, and even a low-quality computer power supply can sometimes place noise on the AC circuit. Turn off any high-energy devices in the house, or power the speakers from a different circuit in the house.

Another common hum problem occurs when you attempt to wire your PC speaker output to your home stereo’s auxiliary input. When you connect two separate systems in this way, a ground loop sometimes occurs because of the different voltages at both ends of the “ground” wire. Use a ground loop isolator-such as the $29.95 unit from Xitel Pty., Ltd. (http://www.xiteldirect.com)-to isolate the PC speaker output from the stereo’s auxiliary input ...