[BC] bit rate and audio

[Mark Humphrey]

On 1/16/06, Goran Tomas <goran.tomas at email.htnet.hr> wrote:
>
>
> FMeXtra seems like a good concept to me, though. Bitrate is a bit too
> low, but other than that I don't see any serious drawbacks.
> Admittedly I don't know much about how good it is at handling
> multipath, mobile reception, etc. and what's expected coverage...


I haven't tried FMeXtra yet, but based on prior experience with FM
subcarriers, I would expect it does not perform well under multipath
conditions.  Mobile reception might be OK in some markets if carried on a
good strong signal (think rural Florida, listening to a nearby Class C
station)  but it will probably not play well in problem zones like the wrong
side of the hill or behind the big buildings.


> It's interesting that the author concludes early in the article that
> audio quality will not be a driving force for any digital system.


"Audio quality" can mean so many different things.  If we're simply talking
signal-to-white-noise ratio, digital usually does deliver a dramatic
improvement that everyone can appreciate.   Of course, the "quality" of
lossy codec schemes is more subjective.

However,  if the listener buys a digital radio hoping for "seamless"
reception within the station's intended service area, but the system doesn't
provide adequate fill-in capability (in a "dead spot" the decoded digital
signal generates obnoxious artifacts or drops out completely) then it will
be perceived as having inferior "quality" to analog.  European DAB was
specifically intended to address the dead spot problem, but the IBOC system
leaves much to be desired in this area.

Mark