[BC] Sangean HD component tuner and Infusion portable Internet radio

[Robert Orban]

At 04:50 PM 12/20/2006, Dana Puopolo wrote:
>Bob,
>
>Why would anyone employ peak limiting or any kind of aggressive processing on
>HD? It makes absolutely no sense! Run the gain down 8-10 db and keep the peak
>limiting OFF!

If you did this on the HD1 channel, the crossfade between the analog and 
digital channels would cause the digital channel loudness to drop 
dramatically and annoyingly and the analog channel to blast at the listener 
who had just readjusted her volume control for the digital channel.

If you're talking about an HD2 channel, maintaining approximate loudness 
parity between the HD1 and HD2 channels avoids annoying volume changes when 
the consumer switches between channels. Having a station "blast" at you is 
particularly annoying. We know this from experience with television, where 
commercials that are significantly louder than program material have 
generated spontaneous consumer complaints to the FCC as early as the 1950s. 
"Joe Sixpack" prefers comfortably consistent program loudness and does 
*not* want to have to constantly fiddle with his volume control.

Fortunately, the amount of digital-channel peak limiting required to 
maintain parity between the analog and digital channels is not very large. 
If you use a good look-ahead technology, you will hear no overt artifacts 
and only the slightest loss of transient punch compared to the source. To 
put this in perspective, the amount of digital channel peak limiting 
required to achieve analog/digital loudness parity is significantly less 
than the amount of peak limiting routinely applied to today's CD releases 
in mastering.

Bob Orban