USB 1.1 Audio spec limitations

[AstroBenny]

From: http://amimuse.com/2012/09/asynchronous-usb-audio-class-2-0/

 

" What, then, are the limitations of the USB 1.1 audio spec? USB 1.1 supports a maximum throughput of 10Mbps (megabits per second). For audio, you need to fix, or maintain, a particular frequency, and doing so prevents you from using the full 10Mbps. That is why USB 2.0 and USB 1.1 devices are limited to 24bit/96kHz audio. "

 

Wouldn't the 10Mbps max throughput be a bottleneck? Why would you not be able to use the full 10Mbps?

[porina]

A single uncompressed "CD quality" stream would take just under 1.4 Mbps so there would appear to be plenty of bandwidth left over even at the older standard. Now we have to caution, I'm not sure if the 10Mbps is the raw data rate, or what's left over after overheads. Not an expert on USB by any means, but I thought audio was transferred using isochronous transfers. In effect, it gets sent when it is needed with a small buffer on the downstream device. Don't see why other data couldn't be sent outside the above, obviously providing the available bandwidth isn't exceeded and/or prioritisation is done.