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Steve Tuzeneu
Sonshine Media

HD Radio: An Opinion





The first order of business in the article is to issue a disclaimer.  The opinions expressed in this article are those of the author.  Now that the disclaimer is out of the way, I would like to share some thoughts about H.D. Radio. 

Back around 2002, H.D. radio was called IBOC, which at the time stood for In Band On Channel.  The fine folks at Ibiquity developed a software method of placing a sub carrier on the A.M. and F.M. bands.  The sub carrier was so many dB below the main channel, about 70; that has since changed to allow for greater coverage, at least for F.M. Stations.


The idea was to enable A.M. and F.M. stations to broadcast in a compressed digital format. This digital transmission methodology was supposed to bring compact disk audio quality to over-the-air F.M. broadcasting. F.M. stations are able to broadcast two additional digital sub-carriers of  slightly lesser quality than the main digital channel.  A.M. stations, however, are only able to broadcast one digital sub-carrier, giving an F.M.-like sound.

Since H.D. radio came into existence, I have read a number of reports where adjacent channel A.M. signals were completely wiped out from the side band interference.  Some major broadcasting groups have stopped using H.D. during evening hours, and others have shut it off altogether.  It would seem that A.M. H.D. is dead, or very close to it.


F.M. H.D. radio, on the other hand, seems to be alive and well in some markets.  Many public radio stations have upgraded their equipment to handle it and are actively programming their H.D. 1 and H.D. 2 channels with alternate music formats and talk programming.  In medium and large commercial markets, you will find a fairly large assortment of channels offering talk formats, and  “B” cuts from popular artists. I have had the opportunity to listen to an H.D. channel which mirrored its analog main channel.  While it sounded pretty good to me, the “wow” factor seemed to be missing.  When the technology was new, and until recently, the digital sub-carrier could only be heard up to one-half the distance of the analog carrier.  Many stations have now increased the injection level so the coverage area is much improved, but not quite as robust as the analog; once you lose the digital, it “blends” to the analog.


While I think it's great that F.M. stations have the opportunity to program additional signals, what I want to know is: who is listening?  H.D. has been heavily promoted in some markets and we still don't see it catching on.  One engineer I spoke with told me his station never receives phone calls when any of his H.D. signals go off the air.  Many of the consumer electronics stores still don't have a clue about this technology and will often confuse it with Sirius-XM.


To me, at this point in time, H.D. seems like a technology that just isn't catching on. I often wonder if it ever will.  I also wonder if it makes sense to invest in all the equipment and licensing fees for something that doesn't seem to be paying for itself.  Maybe VuCast, which gets little press coverage, would make more sense, at least from a financial perspective.


Steve Tuzeneu is an experienced radio station manager and engineer and is the Director of Engineering for Sonshine Media, LLC.  You may reach him at: