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Bad Encoder Settings on HD AM?

dbdigital (and everybody) sorry to get you (us) sidetracked, but I love photography too! Thanks for the info! ;)
 
FTL_Ian said:
It is indeed insane to encode talk in stereo when you have limited bandwidth as AM HD stations have.
Click to expand...

Yes, but don't the IBOC snake oil peddlers tell us that this marvelous "HD Radio" system is supposed to bring music back to the AM band, along with curing cancer and winning the war for the Allies?

(Sarcasm mode off)
 
Wow, I was excited - some reasonable cost HD radios were released yesterday; two from Dual Electronics. Here's the specs for the new Dual XHD6420 and XHD6425 radios that feature these specs:

CD Freq. Response: 10Hz-20KHz
FM Freq. Response: 30Hz-13KHz
FM HD-R FResponse: 30Hz-20KHz
AM Freq. Response: 240Hz- 3KHz
AM HD-R FResponse: 30Hz-4.4KHz
AM Sensitivity: 22uV

So tell me, how the hell is 4.4KHz for AM-HD "near FM quality"? What crap. The HD boys shouldn't let them sell crap like this. The AM sensitivity is for s**t too. I thought the idea was to make a better AM radio when HD was involved? My 1989 GM Delco radio and 1999 Chrysler RAZ radios have better AM frequency response and sensitivity than these goofballs!
 
That's strange. My JVC car receiver specs lists HD AM as going up to 15 kHz.
 
That AM spec MUST BE for analog. There's no reason to roll-off highs on AM or FM HD. More interesting to me is why CD frequency response starts at 20hz (according to the spec), but HD (AM or FM) start at 30hz. Since the audio goes through the same digital to analog converter, they'd have to actually add extra circuitry (or software) to create the rolloff described in the bass. I highly doubt it. This proves (to my satisfaction) that the "specs" weren't created by an engineer, or by any type of measurements, any more than power measurements on audio gear were in the dark days before regulation of power specs.
 
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