Expensive? My HD Radio cost a hundred bucks. The difference with fm ISN'T frequency response (what I suppose was eluded to with the "32khz to 44.1khz" argument...32khz having no relevance to the discussion of an ANALOG format like fm stereo!), it's the lack of noise and distortion, the nearly perfect stereo separation, all on simple equipment. Can fm stereo sound as good? Pretty much, yeah...with, say, a Magnum Dynalab, Fanfare, or Day Sequerra, etc tuner, a roof antenna, and rotor. A few thousand dollars worth of gear for a level of received quality similar to my 100 dollar Accurian, with a 30 dollar INDOOR antenna. Again, if you don't believe the quality can be spectacular, check out this from my website
http://www.theproductionroom.net/hd.wma
Particularly, pay attention to the quality of the classical station at the first of the clip...full bandwidth, no "HD2 Stream", very wide dynamic range. Note the sudden musical crescendo...the so called "jump factor" that the audiophile press refers to as music suddenly becomes much louder. How long since you've heard THAT on analog radio? As impressive (or more) than the music is the complete naturalness of the announcer's voice, and the total lack of ANY background noise. This on a station about 70 miles away.
Now WDAV has a very clean analog signal, too. But where I notice a HUGE difference is during loud passages. There is a "congestion" when attempting to squeeze a gallon (orchestra at full tilt) into a quart container (analog fm...with both the 75us pre-emphasis curve limiting high-level high frequency response, and noise limiting dynamic range). Switching from analog to digital during a complex, LOUD passage should convince anyone WITH EARS of the superiority of FM HD.
Again, I'm no AM HD fan (trying hard to be agnostic, although I must admit my inclinations are against it! Take a local example...WKSK in West Jefferson, NC. They have a new transmitter, new tower, new audio processing, state of the art audio chain (all digital...except for the occasional lp cut played on a bluegrass show). Pretty cool for a small market am station. On the air, they simply sound super. Anyone who says analog AM can't sound good should hear this station (maybe I should post a cut!) But their internet stream, IN STEREO is fantastic. Perhaps streaming using a service like Live 365 is the way for AM to go (I mention them because Live 365 doesn't charge more for bandwidth usage as audience size increases...a REAL plus for stations on a budget! Do it yourself, and the more listeners you have, the poorer you become as bandwidth costs literally eat you alive!) Live365 also takes care of music licensing for the station. Ka-Ching...another big plus.
No the bandwidth doesn't exist for EVERY station to serve thousands of listeners via broadband, and wireless internet audio in cars (in-car listening is where station fortunes are made or broken)is still a pipe dream. But many workplaces have wi-fi. So do public libraries, restaurants and coffee shops, hotels, downtown areas in cities, etc. And if you don't mind paying an arm and a leg, it's available widely from cell-phone providers. What I'm saying is that there IS an alternative to HD for AM stations NOW. And it actually sounds better than AM HD ever could!
HD is here to stay. Nothing anyone could post here could stop that. I remember all the people who said "AM Stereo won't last!" Well ya' know what? AM stereo is still being installed in cars 24 years after it's introduction, new radios are coming out, and there are certainly more AM Stereo stations in America now than AM HD. Better technology doesn't go away. Even if HD doesn't achieve the level of success it's proponents hope, it ain't all or nothin' guys. That sure as hell doesn't mean it's going away. It's here for the duration. Live with it!