Microsoft KB Archive/813498

= Speaker Distortion and Noise with USB Speakers at a High Volume =

Article ID: 813498

Article Last Modified on 2/11/2003

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APPLIES TO


 * Microsoft Windows XP Professional Edition

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SYMPTOMS
When you play an audio file through your USB speakers, you may hear distortion such as a popping or crackling noise. This symptom may occur about every minute when your USB speakers are at a high volume.



CAUSE
This issue may occur if your Intel Mobile Pentium III processor is using Intel SpeedStep technology. SpeedStep requires that the processor restart and have its attributes modified several times a second. The USB sound system relies on a data stream that is reaching codecs at a steady rate for good playback. This issue occurs when the two processes conflict, so the data stream is disrupted. This disruption causes the distortion such as a popping or crackling noise.



WORKAROUND
To work around this issue, turn off the SpeedStep functionality during the sound session. To do so, set the power scheme to an non-adaptive mode:
 * 1) Click Start, click Control Panel, and then click Performance and Maintenance.
 * 2) Click Power Options.
 * 3) On the Power Schemes tab, click Always On in the Power schemes box, and then click OK.



MORE INFORMATION
For additional information about a similar issue with SpeedStep, click the following article number to view the article in the Microsoft Knowledge Base:

318682 PRB: Poor Performance When You Preview Video

Keywords: kbprb kbsound KB813498

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