Re: Is Broadcasting In HD On AM Worth The Problems It Creates?
I was having this very conversation with a good friend of mine just the other day. The answer would depend on your actual 'use' of AM radio.
I have two HD receivers: one at home (Sangean HDT-1) and one in one of my cars (older Sanyo in-dash unit). After hearing both music programming and talk programming in HD, I said that once you hear it for awhile, going back to analog is tough. That said, there's ups & downs for both.
If you're a DX'er, HD/IBOC will more or less kill your hobby in the traditional sense. Whereas the old way of tuning distant signals on adjacent channels will either be blocked totally or interfered with to the point where any enjoyment of the hobby is diminished by all the noise. I actually let my membership in the NRC lapse, due to the fact that a good chunk of the membership refuses to adapt to the changes in technology and all I heard was complaining about HD/IBOC noise on frequencies they would normally not listen to otherwise. (i.e. "WDCD has IBOC running tonight, they're totally blocking 1530 Ohio & 1550 Windsor" ). After months of those style of posts on their email lists, it just got old and i moved on. Rather than take up the challenge of DXing a new mode of transmission (as many did with HDTV), they whine that their 60 year old tube sets cant hear the French language station they've heard a million times already, and that they would never listen to under normal circumstances anyway.
If you're a regular listener dialing in local stations (as the vast majority of listeners do), I'd say that HD is an improvement over analog, but that HD-AM still needs some improvment. The codec used is not the greatest. There's plenty of digital artifacts in the audio. Attempts at stereo transmission degrade the audio quality even further (IMO). It's proven to be damned difficult to get directional antenna arrays to properly tune up with HD running, the result being a less than stellar HD signal. AM-HD brings a lot of problems to the table that simply dont exist with HD-FM. But even with all that, it's still better than Analog if you have a good receiver and/or antenna. It's a young technology and it has a ways to go before it's perfect, but unlike AM Stereo this actually has a chance of surviving if the market can get it to the public (much better than they do now) with usable equipment (not $200 table radios) and if station owners stick with it for the long term.
While we're talking about it: HD on FM? Well, outside of the prospect of offering multiple channels of audio over one station, there's really no real need for it. It doesn't decode/lock well in the fringes, adjacent channel usage renders HD reception very tough or even impossible in certain circumstances. The power levels currently used are insufficient. And there's a only a negligible improvment in audio quality, that only audiophiles would discern.
