Is it my radio?

[NHRadio]

Just got a new JVC head unit installed. When it gets an HD signal, sometimes it sounds terrible.
Example: WEVO (NH public radio) sounds fine in HD. But...
WMLL Manchester NH sounds like the treble has been boosted WAY up. Thin sounding with no bass. Truly awful.
WZLX Boston sounds treble boosted too but nowhere near as bad as WMLL.
WBZ Boston (AM 1030) sounds hollow...like its been overly squashed.
Should I call the stations and tell them? Any ideas? Thank you.

 

[rbrucecarter5]

Just got a new JVC head unit installed. When it gets an HD signal, sometimes it sounds terrible.
Example: WEVO (NH public radio) sounds fine in HD. But...
WMLL Manchester NH sounds like the treble has been boosted WAY up. Thin sounding with no bass. Truly awful.
WZLX Boston sounds treble boosted too but nowhere near as bad as WMLL.
WBZ Boston (AM 1030) sounds hollow...like its been overly squashed.
Should I call the stations and tell them? Any ideas? Thank you.

First of all, welcome to the world of HD radio! I own 3 - not out of any love for the technology, but because that is the only way I can get formats I like. Which may be the ONLY thing that is keeping HD radio going.

Actually, you are doing very well if you are getting HD decode. HD reception is usually quite a hurdle, and it sounds like you have overcome the reception part.

There is nothing WBZ can do to improve AM HD. The channel spacing of the AM band dictates narrow channels - too narrow to get sufficient bitrate for high quality analog. The very best you can get is digital audio reminiscent of streaming over medium speed internet connections. Personally, I find the audio fatiguing after a few minutes - even on speech. Music formats suffer a lot more than talk. Still, if you can get decode on HD, you may notice less static - but beware because dropouts into loud interference from powerlines can be quite abrupt and startling.

I think you might have more luck calling the FM stations about the equalization. But you may be experiencing flat, unprocessed audio. This is a major plus for audiophiles who what a flat response coming from the station, and they can then tailor the response for their listening environment. When you are used to processed audio - flat response can sound a lot like you describe. That, of course, assumes the station is tailoring its response for audio purists. The vast majority of stations just pipe the analog audio straight into HD-1, and it sounds just as processed, but without roll offs on the low and high ends. HD is what the station makes of it. If the station cares enough about quality to only run HD-1, the results can be quite good on a high end system. The moment they add an HD-2, much the advantage vanishes and the result is audio that is about equivalent to a good analog signal chain. Of course, you have two of those on one station, so again the advantage is that niche formats like the ones I want can actually be available in an area, where they wouldn't be otherwise. And lets face it - unless you have a really high end Dr. Dre or Bose audio system in your car, you won't hear any difference between HD radio and analog anyway.

 

[tomservo]

rbrucecarter5's probably on the right track. After years of hearing a 15 kHz brick wall on analog FM, the added treble can sound really out of place on the radio. Where I live a few HD stations sound this way, too. Maybe the HD is fed after the analog equalization and the station's boosting the high end too much, or maybe it's just bad settings on the encoder. We have a Clear Channel country station that sounds exactly as WMLL in Manchester is described. The HD sounds truly awful… you can ask the station, IF you can find anyone who a) listens or b) cares about the HD.

 

[nd2023]

The treble might be aliasing from low bandwidth. This could happen if the station has multiple subchannels, or if the HD2 is a much lower bitrate than the HD1.

I've found that most AAC+ streams sound better than the same station on an HD radio.

 

[satech]

HD Radio often sounds excessively bright because it uses fake treble, that is simulated based on harmonics of lower frequencies ("Spectral Band Replication"). These artificial harmonics often sound harsh and sizzly.

With a 96 kbps HD stream, everything above 9 or 10 kHz is fake, which isn't too bad. But when you get down to 32 kbps, everything above 5 kHz is fake, which puts those sizzly fake harmonics right in the upper midrange "presence band", which your ears are the most sensitive to.

 

[frankberry]

This is a perfect example of "digital doesn't always equate to better fidelity." Analog may have it's drawbacks but it is clean without the digital artifacts of IBOC.

 

[spunker88]

After years of hearing a 15 kHz brick wall on analog FM, the added treble can sound really out of place on the radio.

HD stations brickwall at 15 khz as well, at least the several stations I sampled from the XDR-F1HD all did when I analyzed the audio in audacity. AM-HD stations can also get up to 15khz which is an advantage over analog but the compression is so heavy that I'd rather take 10khz of clean analog audio.

The bad sounding audio on the FM HD stations is likely not your receiver. Chances are since nobody is listening to the HD stations and the audio engineering isn't the best. WBBS nearby me sounds terrible in HD, but thats because they are running a classic country format on HD2 that sounds somewhat decent, it must be getting all the bandwidth.

 

[iyiyi]

Of course it is the station, and HD in general! Everybody knows that a $100 radio can easily assess the quality of $ six figure broadcast equipment! I agree that many HD stations sound extremely harsh and sibilent. I believe that the cause of this is not HD or digital. The main problem with the audio is people who don't know dick about audio processing. Sounds like some of them are running FM processing (including pre-emphasis!) on a digital platform. Either a great deal of "audio engineers" have their heads up their asses, HD's "enemies" are deliberately doing this to prove their "point"; or both!

 

[KB1OKL]

Either a great deal of "audio engineers" have their heads up their asses, HD's "enemies" are deliberately doing this to prove their "point"; or both!

I believe a great deal of HD's "enemies" are engineers who would have liked HD had it worked at all well instead of being the aural albatross it is.

 

[tomservo]

After years of hearing a 15 kHz brick wall on analog FM, the added treble can sound really out of place on the radio.

HD stations brickwall at 15 khz as well, at least the several stations I sampled from the XDR-F1HD all did when I analyzed the audio in audacity. AM-HD stations can also get up to 15khz which is an advantage over analog but the compression is so heavy that I'd rather take 10khz of clean analog audio.

The bad sounding audio on the FM HD stations is likely not your receiver. Chances are since nobody is listening to the HD stations and the audio engineering isn't the best. WBBS nearby me sounds terrible in HD, but thats because they are running a classic country format on HD2 that sounds somewhat decent, it must be getting all the bandwidth.

I wouldn't think the HD would be limited to 15 kHz as well but after looking at a sample of a local station with a particularly clean signal, I gotta say, damn, you're right. There was a steep roll off around 15750 Hz and by 16200 it was pretty flat.

 

[Savage]

Another outrageously uninformed and preposterous post: oh, yeah, HD's problems are the fault of "audio engineers who have their heads up their asses" and anti-HD zealots. Nooo problems with HD Radio as a system! : Nosiree! Nope, it's lazy engineers and "haters" (code for anyone who opposes this technical train-wreck which costs the radio industry more listeners, AM & FM, every day.)

Talk about an insult to radio professionals everywhere - plus a dose of conspiracy-theory paranoia to boot.

Earth to iyiyi: in this industry corporate radio, which has picked a really slow, spavined, nasty and terminally ill horse in the form of HD in the digital horserace, is overburdening beleagured engineers with a massive maintenance hog which is a headache when it craps out (which it frequently does) and is even worse when it doesn't.

And "enemies" are somehow making HD sound harsh and screechy?? Read the posts for pertinent and accurate descriptions of why this actually happens. It's.....the....SYSTEM. Read that?? It's a lousy fake-sounding codec which doesn't play well with other digital sources, multitides of which exist in the real world of radio today.

On time-tested analog FM, the system's superiority is evident on receivers costing $100....and some selling for far less....with no problems. Or are you suggesting that HD will catch on once everyone wises up and starts buying $400 radios (thus to "properly appreciate the wonders of HD?") Is there anything about radio you DON'T misunderstand??

 

[Ai4i]

Takes me back to an exchange I had with a fellow student going home from school on a bus back in the middle 1960's.
I had a portable FM transistor radio and this kid who had not been exposed to radio other than AM, suggested that my radio was not correctly tuned to the station.
I remember originally feeling that FM did not sound like radio.
In my youth, I was a fan of heavy audio processing, but then 1 Corinthians 13.11 reared its lovely head.

 

[Savage]

Thanks for the cite. I don't think the complaints about screechy, vaguely chorusing audio with HD digital are a case of "that's what clean pure unprocessed audio sounds like. All of you radio nitwits have had your heads and ears all twisted from decades of listening to BL-40 Modulimiters."
Give me a break.

No, HD is a system designed with heavy input from COMPUTER wonks - therein lies the problem. HD does not exist in harmony with its intended enrvironment. The codec, particularly on AM, is fatiguing and fake-sounding, especially in the replicated upper registers. It's an outdated algorithm which all too often sounds vaguely like an internet stream. And of course, then there are the multitudes of other attendant problems like processing delay, incompatibility with the analog, self- and adjacent-channel interference, massive waste of energy at the Tx site and, and and....

Hey - keep reading in 1 Corinthians to 13:12. "Now we see a poor reflection as in a mirror; then we shall see face to face. Now I know in part; then shall I know fully......" Paul could have been writing about HD's codec....

 

[satech]

The problem with the HD Radio codec (appropriately named "HDC") is that it's proprietary. Nobody except iBiquity knows what's in it or how it works, other than the fact that it uses SBR "fake treble". It is spectulated to be a "modified" (read: reverse-engineered to avoid licensing fees) version of HE-AAC, but its real-world performance is clearly not as good as HE-AAC at equal bitrates.

 

[iyiyi]

Another outrageously uninformed and preposterous post: oh, yeah, HD's problems are the fault of "audio engineers who have their heads up their asses" and anti-HD zealots. Nooo problems with HD Radio as a system! : Nosiree! Nope, it's lazy engineers and "haters" (code for anyone who opposes this technical train-wreck which costs the radio industry more listeners, AM & FM, every day.)

Talk about an insult to radio professionals everywhere - plus a dose of conspiracy-theory paranoia to boot.

Earth to iyiyi: in this industry corporate radio, which has picked a really slow, spavined, nasty and terminally ill horse in the form of HD in the digital horserace, is overburdening beleagured engineers with a massive maintenance hog which is a headache when it craps out (which it frequently does) and is even worse when it doesn't.

And "enemies" are somehow making HD sound harsh and screechy?? Read the posts for pertinent and accurate descriptions of why this actually happens. It's.....the....SYSTEM. Read that?? It's a lousy fake-sounding codec which doesn't play well with other digital sources, multitides of which exist in the real world of radio today.

On time-tested analog FM, the system's superiority is evident on receivers costing $100....and some selling for far less....with no problems. Or are you suggesting that HD will catch on once everyone wises up and starts buying $400 radios (thus to "properly appreciate the wonders of HD?") Is there anything about radio you DON'T misunderstand??

Even HD haters agree that SOME HD stations sound good. If it was the "system", NO HD stations would sound good. A one million dollar radio would sound lousy on HD to the ears of a pessimistic, pedantic person.

My personal interest in AM HD is to provide a robust, stable platform for digital broadcasting. When I understood that IBOC would employ ISB (as opposed to the 8VSB of HDTV), I jumped aboard the IBOC bandwagon. The current IBOC modulation scheme supplies a rock solid foundation to construct a viable lattice for digital data in the MW band.

Modulation and CODEC (COde/DECode) methods are the domain of the DSP wonks, not mine. From what little I know about it; it seems to me that they have a good handle on a real-world DSP for IBOC. Since it is a proprietary, arcane codec there is an awful lot of "speculation" from soi-disant HD codec "experts". You got me on the fact that I misunderstand radio. I've chiefed radio stations from Maine to Florida. Not because I know dick about radio but because I'm just another BS artist.

Regardless, nothing would ever make me believe that the vast majority of HD radio's current audio problems are NOT caused by people unknowledgeable about digital radio; without the slightest clue of the purpose and setup of audio processors and/or folk anxious to help HD fail. Audio processing per se is very important to good sounding radio. You don't set them "by the book". Processing is set up by using a "knowledgeable ear".

There are just too many "radio" people rabid about a new system that they know nothing about and are unable to understand. Peace...
-

 

[spunker88]

I wouldn't think the HD would be limited to 15 kHz as well but after looking at a sample of a local station with a particularly clean signal, I gotta say, damn, you're right. There was a steep roll off around 15750 Hz and by 16200 it was pretty flat.

I recorded directly from my XDR-F1HD's audio output straight into my computer at a 48khz sample rate, so that anything up to 24khz nyquist frequency would be captured. As a control test I also recorded using the same RCA cable hooked to a CD player and the higher frequency response showed up.

 

[tomservo]

No, HD is a system designed with heavy input from COMPUTER wonks - therein lies the problem.

We may not agree on everything, but this? A-freakin-MEN, brother! I've gone wildly off tangent before on how frustrating life can be for a techie when we leave the computer wonks in charge of everything. They who gave us broadcasts that don't broadly cast, gave us touch screens in cars because why would anyone want haptic feeback from buttons while doing 80 mph? The same people have given us smartphones that are rarely smart at anything, the people who've decided the answer to all life's problems is to stick a computer inside something and let it run Windows CE or some buggy flavor of Linux. Ugh.

 

[clouseau]

Even HD haters agree that SOME HD stations sound good. If it was the "system", NO HD stations would sound good. A one million dollar radio would sound lousy on HD to the ears of a pessimistic, pedantic person.

What you are experiencing here is known as the "But "I" Hate HD Radio" effect. It is what turns normally intelligent and analytical people into absolute idealogues in mere seconds. Normal, "Engineer like" folks abandon their diagnostic abilities and answer a question like "Why do some stations sound good and some sound bad?" and answer it with "The whole system sux." It truly is almost inexplicable.

 

[iyiyi]

Oh those computer wonks!

Gee whiz... Then I wonder where those Ipods, MP3 players, satellite and internet radios, WI-FI and Bluetooth connectivities, CD and DVRs, all-in-one printers, GPS navigation devices in cars and phones and ad infinitum other digital conveniences we rely on daily came from?

I guess it's the one screwup that comes back to bite you. Those "computer smart alecs" just HAD to pee in the pool with that audacious "HD radio" thingie they are trying to ram down our throats...

-

 

[rbrucecarter5]

Oh those computer wonks!

Gee whiz... Then I wonder where those Ipods, MP3 players, satellite and internet radios, WI-FI and Bluetooth connectivities, CD and DVRs, all-in-one printers, GPS navigation devices in cars and phones and ad infinitum other digital conveniences we rely on daily came from?

I guess it's the one screwup that comes back to bite you. Those "computer smart alecs" just HAD to pee in the pool with that audacious "HD radio" thingie they are trying to ram down our throats...

-

Yeah - and how many times do your digital devices lock up, crash, go out in the weeds, do something unexpected or weird? My iPhone gets in a really slow execution mode. Hitting home and power buttons simultaneous to put it in reset fixes it - this happens after I do a lot of streaming, but also at other times. My GPS (which supposedly used HD radio as its traffic source), won't update because its software is out of sync with the computer software. Satellite radio has wierd hops in the audio. DVD and Blu-ray players get stuck in funny modes - the only thing that fixes them is a re-boot. DVR decides to crash when I leave too many recordings on it. HD radios are one of the few things that I own that don't crash, but the audio encoding is really poor on AM - like streaming on a fast modem. It is fatiguing to listen to.

The problem isn't the hardware - it is the software. And I point directly at C compilers that do a poor job translating the language into the target processor's native assembly language. The code is NEVER perfect, you can and do find security holes, undefined states, orphan routines, infinite loops, and all manner of coding landmines that are going to blow the program away. Halt it forever until a hard re-boot. If programmers would get off their lazy butts and learn assembly language, a lot of products wouldn't be failing. But "C" is the mantra, almost like a religion so we are stuck with problems.