Pump Up The Volume With USB

By Ed Tittel

April 9, 2007

(Pump Up The Volume With USB :  Page 1 of 1 )

Microsoft's 2003 introduction of the Media Center Edition of Windows XP helped propel a growing synergy between PCs and entertainment systems that continues unchecked to this day. One unsung player in this ongoing convergence of computing and entertainment is the humble USB connection.

The USB link enables the connection of not just on PC gear, but also various types of home-entertainment equipment. These include audio-video receivers, DVD players--including high-definition versions such as Blu-ray and HD-DVD--and even cable and satellite set-top boxes.

Making sense of this sizable collection of gear becomes easier if you approach the USB connection in either of two ways:

• USB as the pathway to audio coming out of a PC. This can involve various kinds of signal processing or delivery, typically in the form of inline sound cards and signal processing.
• USB as a mechanism for attaching audio devices into entertainment systems. As a way to add more inputs alongside existing audio and video capabilities.

In this article, I will survey both these areas. I will emphasize the ways system builders can use this information to serve their customers and expand their business.

USB AS THE PATHWAY FOR AUDIO

USB turns out to be a surprisingly good method for enabling PC audio. Even the relatively old USB 1.1 standard, which tops out at 12 megabits per second (Mbps), is good enough to handle conventional stereo audio and some compressed forms of multi-channel surround sound. (Note: Don't confuse Mbps with MBps; the latter stands for megabytes per second.)

USB 2.0, of course, is even faster--and more powerful. With a raw data rate of 480 Mbps, it is 40 times faster than USB 1.1. That means USB 2.0 offers more than enough speed to accommodate high-definition video and various 5.1 or 7.1 multi-channel surround-sound schemes.

Today's high-definition DVD formats, including HD-DVD and Blu-ray, place the biggest demands on data-transfer rates. HD-DVD rates top out at 36.5

 Page 1 of 1