[BC] Can we now have a serious discussion about audio quality??

[Robert Orban]

With respect, you have come late to the party. All of the issues that you 
raised have already been discussed to death on this list. I suggest that 
you go through the archives and read through some of the conversations. I 
find myself unable to muster the energy to even write a short summary.

Suffice it to say that maintaining quality on IBOC requires uncompressed or 
very lightly compressed sources plus audio processing that is optimized for 
the digital channel. All of this is under the broadcaster's control and all 
is available today. Like anything else, implementing IBOC successfully 
requires attention to detail and many broadcasters are still climbing up 
the learning curve.

Bob Orban

At 10:00 PM 12/23/2005, you wrote:
>Date: Fri, 23 Dec 2005 15:55:42 -0700
>From: VideoPaul at aol.com
>Subject: [BC] Can we now have a serious discussion about audio
>         quality??
>To: broadcast at radiolists.net
>Message-ID: <6.2.3.4.2.20051223155502.02e07e30 at broadcast.net>
>Content-Type: text/plain; charset="us-ascii"; format=flowed
>
>In a message dated 12/23/2005 2:49:45 P.M. Central Standard Time,
>lists at loudandclean.com writes:
>    Performance in full digital is the real "pig in a poke" about
>HD as developed by Ibiquity.  As I read their white papers,
>when we (the industry) turn the analog off, the _existing_ IBAC
>carriers get turned up, and we get to add additional IBOC
>carriers where the analog was, but at a lower level than the
>IBAC carrier groups.
>
>    This means that the receivers must be able to receive
>'interleaved' carrier groups, where a lower-first-adjacent
>interferer will have it's high-level upper IBAC carrier group
>within the area where the desired station's low-level IBOC
>carriers will be.
>
>This is all well and good, but I do not think that the end of analog
>broadcasting is nearly as close at hand as Ibiquity thinks it is, and
>NO ONE has addressed the fact that IBOC as currently presented has
>unacceptably LOW audio quality.  The MPEG-like artifacts are
>everywhere in the high end.  Multicasting means taking data away form
>the main channel and making it sound even worse.
>
>I have gotten several people from my company in the truck and sat
>them down to listen to IBOC.  Without giving any opinion one way or
>the other, I put on a local station, which of course will first come
>up as analog.  Then they hear the switch to the digital and they all
>asked the same question.  A typical conversation:
>
>"What happened to the audio??"
>You're hearing the digital audio signal now.
>"That's the digital?"
>Yessir.
>"It sounds worse!  Let me hear the analog again"
>(switching around it made and the A/B comparison is given)
>"The digital sounds worse.  Why would we spend all that money to put
>this on the air?"
>
>I save face by telling them that this is a new technology and it
>should get a lot better, but no one seems to be actively addressing
>the problems with the digital audio.  Exactly WHY can't we process it
>aggressively?  If the data rate is the issue, shouldn't we be
>pressing Ibiquity for a higher data rate, at least working towards
>more audio data once analog goes away?
>
>There are a couple of schemes out there for a digital subcarrier that
>rides the main analog signal and isn't 20dB down, and doesn't have
>the audio problems that the IBOC does.  But, they don't allow for
>multicasting and don't allow a lot of room to SELL DATA so they are
>likely to get fought tooth and nail.
>
>To those companies that are heavily invested in playing MP3s on the
>air (you know who you are), is there any movement to addressing the
>destructive nature of cascading codecs?  Taking something that has
>been transcoded to and from MP3 and then crammed into the even
>smaller IBOC data bucket starts to exhibit some very annoying artifacts.
>
>Before we go too far down this road, is it unreasonable to ask for
>better data and coverage out to our protected contours?  More to the
>point, we as terrestrial broadcasters can offer something that the
>satellite boys cannot:  DECENT UNCOMPRESSED AUDIO!  XM and Sirius
>will always have to hyper-compress their audio data.  Do we care
>about our listeners so little that we are willing to subject them to
>artifact filled music with that "springy" sound in the high end??  We
>beg them to not go to satellite or iPods and then give them worse
>audio to listen to.
>
>When I had the opportunity to question this at he B-E HD Radio
>seminar at NAB, I heard all about the wonderful data services they
>want to sell.  I asked Jeff Detweiler directly if I had this
>straight...that with the 300kB of data they will be able to pass in
>the utopian world where analog radio had been killed off, that they
>will be dedicating LESS THAN A THIRD of that data to the analog audio
>program.  He said that my understanding was correct.  I questioned
>whether or not it made sense to ANYONE that we in radio, who are
>supposedly in the business of getting decent quality audio from here
>to there, weren't even committing HALF of the eventual bandwidth
>to--as silly as it seems--AUDIO!  I was told that there were so many
>opportunities to sell data that this wasn't considered to be an real concern.
>
>I then asked the real land mine question:  If there might be any way
>for some poor, misguided broadcaster whose understanding of the
>industry were so hopelessly out of whack that he wanted to actually
>deliver BETTER audio to his audience would be able to dedicate more
>than the 96k of audio that Ibiquity felt was adequate.  The entire
>room heard the answer:  No, that was not being worked on in any way.
>
>Okay, rant mode off.  Flame away, I got big shoulders.
>
>--Paul Strater