AM BROADCASTERS - CALL TO ACTION

[tomservo]

I've compared the analog audio on those stations myself and found WBAP sounds no better and no worse than KLIF and KRLD. Gotta call BS on you there. Having made the same comparison, I put as much stock in statements like these as I do with esoteric hi-fi nuts.

Just because you don't hear a difference doesn't mean one doesn't exist. I can pick out a chopped down analog signal on some radios from quiet casual listening; other radios in other environments don't yeild the same results. In the car, it's so obvious that I am appalled that others claim there is no difference. I can only assume you have bad hearing or an awful radio. Or both.

More likely, it's just personal preference. I'm sure there's noise that you can pick out well, that bothers you immensely, that some of us casual listeners might not notice.

Since you hear so much difference in these stations, would you mind explaining something? You listed three talk stations. The human voice typically has a response of 80hz to 1100hz, well under 5khz. Does the traffic sounder and bumper music sound that much better to you on WBAP? Here's a hint, most normal people don't listen to talk stations for the traffic sounder and bumper music. They listen for the material in the 80hz to 1100hz range, the TALK!

People may not listen for the sound effects and music beds, but they would prefer a 'clean' sound, don't you think? Muffled telephone audio is adequate, sure... But is it a pleasure to listen to for an hour? No way, unless that's all your hearing aid happens to pass.

Why not just chop all the audio down to 2 kHz; think of all the extra space available for the digital spectrum! Low bandwidth talk on AM is just as fatiguing as overdriven pop music whose highs and lows have been rolled down to nothing in the loudness wars. Or, for me, just as annoying as the digital artfacting that plagues low bitrate audio like XM and Sirius feeds us.

*sigh* on an unrelated note, my car's amplified antenna quit working this week. Looks like I'll miss the so-called impending doom over nighttime AM-HD, since the AM section is now deader than a sack of doorknobs. Last night I was within eyesight of a 100 kW FM station's 880' tower, and the signal meter was registering just 70%! Since I'm not too keen on tearing off the headliner to get to the amp on the roof, I'm gonna just suffer with XM. :'(

 

[dumber than a box of hair]

The human voice typically has a response of 80hz to 1100hz, well under 5khz. Does the traffic sounder and bumper music sound that much better to you on WBAP? Here's a hint, most normal people don't listen to talk stations for the traffic sounder and bumper music. They listen for the material in the 80hz to 1100hz range, the TALK!

I would love to know where you got this from. Several university web sites say it's 60-4000 Hz...and that upper end is well beyond the rolloff of most AM radios.

People here seem to think it's some great conspiracy that more engineers aren't speaking out about the technology. I have a much more reasoned explanation. Like me, they've heard it and they don't see a reason to. They're content to let the lunatic fringe look like lunatics.

Well, you just called a few dozen of the most respected engineers in the profession lunatics. They just don't happen to be posting here. I've been an engineer for close to 40 years, and I wouldn't put myself in their class, but they all have severe reservations about AM-HD. We'll see in a few weeks if they're right or wrong.

 

[TheRover]

But I think that AM HD broadcasts in the News/Talk/Sports Radio formats all Suck.

Daytime and would obviously suck at Nightime too.

I do not need or want any AM HD broadcasts for News/Talk/Sports Radio, daytime or nightime.

I have absoultely no patience in wating for ANY singal delay or adjustment when tuning in to News/Talk/ or Sports Radio. None ! No patience whatsoever.

I live in a Metropolitan area, and I do not and will not accept AM reception that sound like I'm on the border of their transmissions as this analog to HD switching takes place with each tuning!

Now, for some song, on FM, or AM radio.... I can wait for the transition. But that's it.

 

[radioskeptic]

I can’t let Radioman 100’s outrageous statement in Reply # 37 go unanswered:

Since you hear so much difference in these stations, would you mind explaining something? You listed three talk stations. The human voice typically has a response of 80hz to 1100hz, well under 5khz. Does the traffic sounder and bumper music sound that much better to you on WBAP? Here's a hint, most normal people don't listen to talk stations for the traffic sounder and bumper music. They listen for the material in the 80hz to 1100hz range, the TALK!

For the record, that’s the range (not the “response”!) of most of the fundamentals in the human voice. In fact, it’s greater than the typical range of SPEECH fundamentals. Singing, however, is another matter.

A bass singer’s usual range goes down to the E-natural represented by the first line below the bass staff. That’s 82.4 Hz when A=440. But Melvin Franklin, the Temptations’ bass singer, hits the C below it – 65.4 Hz – on the word “on” in “Ball of Confusion.” And the basses in some Russian Orthodox choirs go much lower. Personally, I’ve only heard them reach an A (55 Hz), though some are said to be able to reach the lowest G on the standard piano keyboard (49 Hz).

On the high end, the usual soprano’s high C –two octaves above middle C – is 1,046.5 Hz, and the D-flat above it is 1,108.7. But coloraturas can go almost half an octave higher. In “The Magic Flute,” Mozart gave the Queen of the Night some F-naturals above that high C – 1,396.9 Hz! – making the role so daunting that relatively few accomplished singers attempt it.

BUT THOSE ARE ONLY THE FUNDAMENTAL FREQUENCIES OF THE VOICE!

Overtones – or, if you prefer, harmonics – are essential for indentifying both vowels sounds and the timbres of individual voices. But even higher frequencies, those representing consonants (especially the fricatives), are necessary for speech intelligibility.

Truly natural reproduction of the human voice requires nearly flat response to at least 8 kHz; but speech intelligibility is generally adequate with response no more than 10 dB down at 3.5 kHz.

Of course, intelligibility and naturalness are two very different things, and a system with response rolled off too low induces listening fatigue very quickly.

Is Radioman 100 so ignorant of both music and acoustics (and psychoacoustics) that he really doesn’t know the difference between the range of fundamental frequencies produced by human voices and the frequency range required for speech recognition? Or is he deliberately trying to confuse the issue?

 

[Radioman100]

I can’t let Radioman 100’s outrageous statement in Reply # 37 go unanswered:

Since you hear so much difference in these stations, would you mind explaining something? You listed three talk stations. The human voice typically has a response of 80hz to 1100hz, well under 5khz. Does the traffic sounder and bumper music sound that much better to you on WBAP? Here's a hint, most normal people don't listen to talk stations for the traffic sounder and bumper music. They listen for the material in the 80hz to 1100hz range, the TALK!

For the record, that’s the range (not the “response”!) of most of the fundamentals in the human voice. In fact, it’s greater than the typical range of SPEECH fundamentals. Singing, however, is another matter.

A bass singer’s usual range goes down to the E-natural represented by the first line below the bass staff. That’s 82.4 Hz when A=440. But Melvin Franklin, the Temptations’ bass singer, hits the C below it – 65.4 Hz – on the word “on” in “Ball of Confusion.” And the basses in some Russian Orthodox choirs go much lower. Personally, I’ve only heard them reach an A (55 Hz), though some are said to be able to reach the lowest G on the standard piano keyboard (49 Hz).

On the high end, the usual soprano’s high C –two octaves above middle C – is 1,046.5 Hz, and the D-flat above it is 1,108.7. But coloraturas can go almost half an octave higher. In “The Magic Flute,” Mozart gave the Queen of the Night some F-naturals above that high C – 1,396.9 Hz! – making the role so daunting that relatively few accomplished singers attempt it.

BUT THOSE ARE ONLY THE FUNDAMENTAL FREQUENCIES OF THE VOICE!

Overtones – or, if you prefer, harmonics – are essential for indentifying both vowels sounds and the timbres of individual voices. But even higher frequencies, those representing consonants (especially the fricatives), are necessary for speech intelligibility.

Truly natural reproduction of the human voice requires nearly flat response to at least 8 kHz; but speech intelligibility is generally adequate with response no more than 10 dB down at 3.5 kHz.

Of course, intelligibility and naturalness are two very different things, and a system with response rolled off too low induces listening fatigue very quickly.

Is Radioman 100 so ignorant of both music and acoustics (and psychoacoustics) that he really doesn’t know the difference between the range of fundamental frequencies produced by human voices and the frequency range required for speech recognition? Or is he deliberately trying to confuse the issue?

If Rush Limbaugh decides to become the next Pavarotti and sing his show every day, this entire spiel of yours might have some merit.

 

[Radioman100]

Well, you just called a few dozen of the most respected engineers in the profession lunatics. They just don't happen to be posting here. I've been an engineer for close to 40 years, and I wouldn't put myself in their class, but they all have severe reservations about AM-HD. We'll see in a few weeks if they're right or wrong.

That's not what I said at all. I said most engineers don't bother saying anything here because they're content to let the lunatic fringe look like lunatics. In other words, most of them are more than content to sit back, do nothing and let the regulars here look like wackos.

If the issues claimed here were so truly damaging, there's no way the technology would have made it onto so many radio stations. The arguments frequently made here would have everyone believe the corporate VPs of engineering of every major broadcast group must have been duped. If they're all so dumb, how did they land their positions? For that matter, how did a dimwit like Tom Ray land a cherry job like WOR?

See, the truth is these are smart guys. Way too smart to get drawn into sophomoric shouting matches here or anywhere else on the net.

I don't think anyone, anywhere has said there will be zero interference caused by AM IBOC. It will cause interference to some degree, but most people think the benefits outweigh the drawbacks. What I find hilarious is the over the top descriptions. Here we're arguing muddy audio, apparently because someone thinks Rush Limbaugh sounds better on a station that goes up to 10kHz, yet the company that owns the network he's syndicated on has limited bandwidth to 5kHz on ALL of their AM properties whether they are HD or not. Why do you suppose that is? The conspiracy theorists (or lunatic fringe, pick your favorite description) would lead you to believe it's all part of selling HD to the public by intentionally making non-HD radios sound bad. After all, it couldn't possibly have anything to do with improving the analog signals, right?

 

[rbrucecarter5]

I guess I was mistaken in thinking you worked or had worked in radio; this is all about consistency and is a prime tenet of broadcasting. One of the first rules of radio programming is to offer what listeners expect every hour of every day, all through the broadcast week. This means that if you have HD, and your listeners start buying receivers, don't yank it away from them should they be listening at night.

Seven years - WAPN Holly Hill, FL.

I was being sarcastic about the nighttime operation.

Listeners are NOT buying receivers in any great numbers.

 

[rbrucecarter5]

As far as reputation goes, I think people saying things like "I have to admit I have my radio on WBAP locally, because KLIF and KRLD sound terrible with muffled audio." are going to be ones whose reputation suffers when more people hear the stations for themselves. I've compared the analog audio on those stations myself and found WBAP sounds no better and no worse than KLIF and KRLD. Gotta call BS on you there. Having made the same comparison, I put as much stock in statements like these as I do with esoteric hi-fi nuts. You know, the ones that claim using certain cables between their CD player's digitial output and their receiver's digital input will allow you to hear more "air" in a recording. Do you suppose the real reason you spend more time listening to WBAP could be the same reason everyone else does too? WBAP has a killer line-up of talent. It's a conservative market and WBAP has both Rush and Hannity.

Since you hear so much difference in these stations, would you mind explaining something? You listed three talk stations. The human voice typically has a response of 80hz to 1100hz, well under 5khz. Does the traffic sounder and bumper music sound that much better to you on WBAP? Here's a hint, most normal people don't listen to talk stations for the traffic sounder and bumper music. They listen for the material in the 80hz to 1100hz range, the TALK!

People here seem to think it's some great conspiracy that more engineers aren't speaking out about the technology. I have a much more reasoned explanation. Like me, they've heard it and they don't see a reason to. They're content to let the lunatic fringe look like lunatics.

I really do not appreciate your attitude towards a fellow member of this board and engineering professional. Perhaps - if you would find Jesus Christ as your personal savior - you would learn how to treat people better. Or at least how you would like to be treated yourself.

That said - the only difference between your listening experience and mine is that the stations sounded the same on your radio. They do NOT on mine. You also made a fundamental error assuming that speech rolls off at relatively low frequencies. Only the fundamental frequency of the complex waveform does. Speech consists of not just a fundamental tone, but also harmonics and overtones. When absent, they make the speech muffled and less intelligible. Now - I realize I've just given HD advocates a major argument for HD, but there is nothing about broadband speech that can't be done using analog techniques. And on a wideband radio, WBAP sound REALLY good - MUCH better than KLIF or KRLD. But I was fair and admitted my car radio is narrowband. But it still passes enough of the speech overtones and harmonics to make a difference.

As far as me being a member of the lunatic fringe - get real! I've been on every audiophile discussion board debunking speaker wire, tube sound, super electrolytic capacitors, and every other audio "religion" out there. I've been doing it with mathematics and specifications - so I am unassailable. Speaking of audio "religions" - HD advocacy is sounding more and more every day like a "religion", with zealots ignoring good engineering and careful observations with all the tenacity of cult members. The same could be said of some HD opponents as well - but I've publically stated on this board: bring it on. Convert as many stations as possible to HD. Then we will see where the interference level is. I've also said that I don't care - the cacophony of Spanish stations at night has already killed skywave so I no longer listen anyway. I am now using Satellite and streaming, and I must say the enjoyment level is much greater than listening to a distant station with poor reception. The marketplace is speaking more eloquently about the issue of HD radio than I ever could. If I were a station owner, I'd only have to look at consumer acceptance levels before I made my decision - NOT to convert.

 

[Radioman100]

I've also said that I don't care - the cacophony of Spanish stations at night has already killed skywave so I no longer listen anyway.

Well, at least we agree about something. I attempted to DX both WBAP and KRLD a few nights ago and both were totally unlistenable. No hiss or buzz, just accordions and singing in Spanish. Just one of the many reasons I find the original poster's appeal to Mexico so amusing. He should listen to some of the shows on his station. The people running that country have no respect for the rule of law.

Oh, and I am a Christian thanks! But it doesn't surprise me that someone from your side of the argument would bring out religion. Most of the discussions I've read here are most un Christ-like even if they don't involve any IBOC supporters. Was it yesterday that I read something about dragging the president of iBiquity behind a car?

Regardless of what everyone here would like to see, there is no analog solution to the bandwidth problem of AM radio. Regardless of whether the stations are transmitting up to 10kHz or not, most receivers don't approach that. I think there is a much greater chance of radio manufacturers producing HD radios than producing radios with more than 4kHz bandwidth. We've been down that road before and manufacturers didn't follow.

 

[Play Freebird]

If the issues claimed here were so truly damaging, there's no way the technology would have made it onto so many radio stations. The arguments frequently made here would have everyone believe the corporate VPs of engineering of every major broadcast group must have been duped. If they're all so dumb, how did they land their positions? For that matter, how did a dimwit like Tom Ray land a cherry job like WOR?

We should all remember that the "major broadcast groups" may be big players, but they aren't necessarily infallible. History is full of examples of market-dominant companies that missed the big picture and ended up bankrupt, and perhaps just as many examples of little guys (once regarded as "lunatic fringe" for speaking the truth) who were later proven correct, because they took the time to challenge conventional wisdom and THINK. And keep in mind that corporate engineers must still answer to managers above them; they aren't completely free to express dissent.

As I see it, the problem is that our "industry leaders" (the top-level managers of NAB and most of the large group owners) were told that "the future is digital", but were then led to believe that mere act of "going digital" (even if the technology was inappropriate) would be enough to assure traditional radio's survival in the marketplace. Initially, IBOC was presented as an appealing alternative; the "decision makers" were told they would simply need to install a digital exciter and make a few inexpensive modifications to their transmitter plants; this would magically provide a crystal-clear digital coverage area that replicated existing analog coverage. No new spectrum, no "leveling the playing field", no need to install a new digital transmitter plant (like the TV people were doing at considerable expense). Digital would be the panacea for AM's shortcomings.

But as the old saying goes, "If it sounds too good to be true.... it probably is!" Both the AM and FM HD systems are full of compromises and tradeoffs, but the Laws of Physics suggest that the negatives will strongly outweigh the positives in our current attempt to introduce in-band digital at medium wave frequencies, while at the same time, trying to preserve the analog signal (the exclusive conduit to many mobile listeners for years to come.)

The FM band is more forgiving, but the Laws of Economics will take control there.

 

[Savage]

Ummm.....actually, here's the truth about major broadcast engineering execs/managers and HD-AM. If you catch almost any one of them in an unguarded moment, with the possible exceptions of Tom Ray and Criss Alexander, they will tell you privately they have grave, not to say growing reservations about IBOC-AM at night. (Had a like conversation with one of 'em at a 50kw top-ten market AM just this morning, who has run HD-AM for three years and was a pioneer in the system.) Still others have grave reservations about it during the DAY. And over the weekend, a major group CE (who will remain anonymous for reasons made obvious in a moment) made a remarkable confession to this poster. His statement may clear up the strident claim by IBOC-boosters that the thundering silence about nighttime implementation is tacit approval of HD-AM.

It seems that, according to this source, the licensing agreement between end-users (stations/groups) and Ibiquity contains a nondisclosure provision PROHIBITING the dissemination of any data, information or opinion which could impede industrywide implemenation of IBOC. Interpreted broadly as any station's counsel might: NO public criticism of the system!! I don't know about you guys but this is an utter bombshell to me. Consider the implication: a system so flawed that, before you're allowed to use it, you have to pledge undying allegiance to it!

Unless my broadcasting/media/electronics history has a glaring defect, I remember no such iron-lung provision for NTSC color TV, HDTV, stereo FM, C-QUAM AM, VHS v. Beta, 8-tracks, cassettes or LP vs. 45 rpm.

Nice system. So valid, so terrific, its perpetrators have to legally muzzle anyone who might have a bad experience with it.

 

[davideduardo]

Convert as many stations as possible to HD. Then we will see where the interference level is. I've also said that I don't care - the cacophony of Spanish stations at night has already killed skywave so I no longer listen anyway.

Many US stations that had "free" coverage at night now have lots of interference as countries to the south have built better AM stations. Mexico, in as high a percentage as in the US, has stations that were approved by first NARBA and then the Comision Mixta and the underlying treaty accords that run as licensed. The fact that Mexico did not have bigger stations has more to do with a more recently developed economy than with illegal operation.

On the other hand, nations like Cuba have no regard for US or Mexican allocations and do not protect them. In most of the Caribbean and Central America, there is no coordination at the international level, so interference can be expected as places like Honduras or Guatemala put high power AMs on the air. This is, in fact, one of the reasons why skywave is not considered valuable to most US stations and why forgoing it's coverage is no loss in listeners.

It's funny to note that in Mexico, stations complain of too much interference from the US, too.

 

[Savage]

Further to the discussion regarding the complex audio and psychoacoustic qualities of human speech carried on a few posts ago among zach and radioman 100: radioskeptic makes an excellent point regarding fundamental frequencies vs. the harmonics/overtones in which the human voice - particularly the male voice - is so rich. Bandpass is only one critical component of overall audio quality.

One of the big complaints about IBOC-AM is that is sounds worst on SPEECH, an ironic fault for a radio transmitting system promoted primarily to news & talk stations. Over and over one encounters anecdotal evidence on this board and elsewhere, that HD-AM reception includes a dull "chorusing" effect on voice which is irritating and fatiguing to the listener (making the very large assumption you're able to locate an HD-AM radio which will lock onto the digital signal long enough for you to tire of the audio.) And the reason: because human speech is surprisingly difficult to replicate, the "artifacting" from HD-AM is most evident on the format boosters insist need audio help the most.

Some engineers opine (privately, of course; see previous post about the muzzlematic licensing provision) that the Ibiquity codec needs major revision to improve voice quality. But don't expect it any time soon. Reports allege there's no more development capital.

Interesting lesson from audio engineering history: until the 1950s it was widely believed that intermodulation distortion was undetectable by the human ear, which explains the single-ended radio and phono amps so prevalent in the postwar period which typically generated intermod of 10% or better. The hi-fi revolution brought on by stereo in the late 1950s was a stunning development to the former solder-jockey, scope-watching, self-proclaimed expert engineering suits who, a generation later, would emerge once again in the incarnation of "IBOC promoters." Hear them trot out the 1950 arguments against high fidelity for a reprise: consumers are dumb. They can't hear the difference between 5 kHz and 10 kHz bandpass. Tell 'em "it's digital!!" and they'll rush out like zombies just to acquire the latest crap. If it's new, it's invariably better. Nobody listens to radio that way anymore. And on, and on, and on....

 

[amfmsw]

What an intelligent discussion on fidelity, reproduction and speech.

Now, let me join with this quiz for Mr100. When you want to eq muddy audio tapes of speech, what's the first spectrum increased? 9-11Kc. That's where human speech has the most distinctive sound: the letter S, D, & T. With audio cut off at 3Kc, it just sounds like crap. No distinct sweetness in the speech.

When my child had speech lessons because of learning disabilities, I spent countless hours on those letter pronunciations. Listen to ANY AM/FM simulcast, and the first thing that hits you is the clarity of speech.

Following your thinking, Radio & TV networks would still be using AT&T Long Lines for feeds. Antone remember hearing Mutual news at the Top Of The Hour on Top 40 radio? Like listening to sandpaper.

And finally, don't believe evrything you read or hear about on the net. Our Rush Limbaugh station is fed in full 15Kc bandwidth. It is fed in full high fidelity, NOT cutoff at 5Kc. Your do not have your facts correct.

 

[Radioman100]

What an intelligent discussion on fidelity, reproduction and speech.

Now, let me join with this quiz for Mr100. When you want to eq muddy audio tapes of speech, what's the first spectrum increased? 9-11Kc. That's where human speech has the most distinctive sound: the letter S, D, & T. With audio cut off at 3Kc, it just sounds like crap. No distinct sweetness in the speech.

When my child had speech lessons because of learning disabilities, I spent countless hours on those letter pronunciations. Listen to ANY AM/FM simulcast, and the first thing that hits you is the clarity of speech.

Following your thinking, Radio & TV networks would still be using AT&T Long Lines for feeds. Antone remember hearing Mutual news at the Top Of The Hour on Top 40 radio? Like listening to sandpaper.

And finally, don't believe evrything you read or hear about on the net. Our Rush Limbaugh station is fed in full 15Kc bandwidth. It is fed in full high fidelity, NOT cutoff at 5Kc. Your do not have your facts correct.

Is your Rush Limbaugh station owned by Clear Channel? Is it an AM? I have lots of friends working in engineering for that company, and several have told me about the 5kHz directive. A few have also told me of improvements they've noticed in signal quality and range as a result of the 5kHz limit they've imposed.

On AM, the hotter and more dense your modulation is the further your station will go. If you're not wasting power transmitting a range of frequencies most modern radios can't reproduce, you can modulate the remaining frequencies that much hotter. It improves coverage and penetration.

Several years ago I worked for CC. There was an engineering conference call and Randy Michaels joined us on the call for a few minutes. He told us he wanted all CC AMs doing 145% positive modulation and 95% negative. He told the engineers that he would gladly take a modulation ticket. He also said if you had any AM plants in your market incapable of 145% positive to get with a regional engineering manager and do whatever it took to fix it.

They're pretty serious about making their AM signals all they can be and then some at Clear Channel. If you're running one of theirs with 15kHz audio, just pray nobody higher up the corporate ladder finds out.

As for the whole AM fidelity argument, you guys are just pushing yourselves further and further out into that lunatic fringe. AM is and always has been plagued with audio quality issues. It's prone to interference from lightning, transformers, power lines, computers, microwaves and just about any other modern electronic convenience. With AM the name of the game is compromise, doing the best you can with what you have to work with.

I think it would be hard to argue that Clear Channel isn't one of the most successful operators of AM radio stations in the country. They own many powerhouse stations with huge ratings and revenue to match. They've decided to take certain steps to maximize their signals and it appears to be working for them more often than not. So the next time you're lamenting the fact that a Clear Channel AM has trounced yours in the ratings, take some comfort in the fact that you can hear the talent on your station in their full sibilant glory on your antiquated radio.

 

[Radioman100]

Ummm.....actually, here's the truth about major broadcast engineering execs/managers and HD-AM. If you catch almost any one of them in an unguarded moment, with the possible exceptions of Tom Ray and Criss Alexander, they will tell you privately they have grave, not to say growing reservations about IBOC-AM at night. (Had a like conversation with one of 'em at a 50kw top-ten market AM just this morning, who has run HD-AM for three years and was a pioneer in the system.) Still others have grave reservations about it during the DAY. And over the weekend, a major group CE (who will remain anonymous for reasons made obvious in a moment) made a remarkable confession to this poster. His statement may clear up the strident claim by IBOC-boosters that the thundering silence about nighttime implementation is tacit approval of HD-AM.

It seems that, according to this source, the licensing agreement between end-users (stations/groups) and Ibiquity contains a nondisclosure provision PROHIBITING the dissemination of any data, information or opinion which could impede industrywide implemenation of IBOC. Interpreted broadly as any station's counsel might: NO public criticism of the system!! I don't know about you guys but this is an utter bombshell to me. Consider the implication: a system so flawed that, before you're allowed to use it, you have to pledge undying allegiance to it!

Unless my broadcasting/media/electronics history has a glaring defect, I remember no such iron-lung provision for NTSC color TV, HDTV, stereo FM, C-QUAM AM, VHS v. Beta, 8-tracks, cassettes or LP vs. 45 rpm.

Nice system. So valid, so terrific, its perpetrators have to legally muzzle anyone who might have a bad experience with it.

Thanks for the tip. Our corporate legal neglected to mention this to us. They're rather adverse to risk, so I have to think they would have said something, but they're only human after all. I guess it just slipped through the cracks.

 

[tomservo]

Is your Rush Limbaugh station owned by Clear Channel? Is it an AM? I have lots of friends working in engineering for that company, and several have told me about the 5kHz directive. A few have also told me of improvements they've noticed in signal quality and range as a result of the 5kHz limit they've imposed.

On AM, the hotter and more dense your modulation is the further your station will go. If you're not wasting power transmitting a range of frequencies most modern radios can't reproduce, you can modulate the remaining frequencies that much hotter. It improves coverage and penetration.

Several years ago I worked for CC. There was an engineering conference call and Randy Michaels joined us on the call for a few minutes. He told us he wanted all CC AMs doing 145% positive modulation and 95% negative. He told the engineers that he would gladly take a modulation ticket. He also said if you had any AM plants in your market incapable of 145% positive to get with a regional engineering manager and do whatever it took to fix it.

I've heard about the 5kHz directive, but not the modulation manifest. Perhaps that explains why many Clear Channel AMs I've heard (more specifically WERC Birmingham and WREC Memphis) have always sounded driven, loud and distorted on my Volkswagen's (software defined?) radio. On the other hand, on more forgiving radios the stations sound "stronger", and punchier... But not really any easider to listen to.

Why not just pull a Clear Channel and go 5 kHz with heavy modulation and processing on talk stations? It sounds like they have an interesting way of tackling some of AM's limitations, without resorting to HD (which they've done in droves, anyway, sigh.)

 

[LinoNYC]

Interpreted broadly as any station's counsel might: NO public criticism of the system!! I don't know about you guys but this is an utter bombshell to me.

Without resorting to "uhmmm" I'd be interested in reading proof of this claim. Clearly, there would be no legal jeopardy in just admitting it's existance and clarifying the limitations.

Some named person will have to step up, otherwise this is more bombast than bombshell.

Lino

 

[SUPERCASTER]

If high fidelity just matters to a very few in the "lunatic fringe" then there is no need for HD radio at all, right?
Most listeners seem to enjoy high fidelity AM and FM, and surveys show less then 1% have said they would ever bother to stop into a store to give a listen to HD radio (much less actually buy even one HD radio).
So HD supporters are clearly the few in the "lunatic fringe", and do not represent the majority of radio listeners.

 

[Savage]

Hey, here's a shocker of a suggestion. As I understand the pro-IBOC arguments, to "save" AM we need:
(a) better audio quality, (b) stereo, (c) perception of AM radio as a quality-sound medium, right? And - given the adjacent-channel issue that keeps being brushed aside, first-adjacent noise really isn't that much of a problem. Have I got these right?

How about this:

(a) Revise the NRSC preemphasis to provide for an ANALOG bandwidth of at least 12 kHz. (Who cares about the adjacent-channel splash? It would be FAR less objectionable than IBOC's steady-state "ffffffff.")
(b) Mandate C-QUAM AM stereo. Most stations already have it installed.
(c) Mandate minimum receiver-bandwidth standards.

Voila! Problem solved. For anyone that's interested, I can link you to an unscoped aircheck of an AM station in Elmira, NY, recorded 10-27-71. The ENTIRE chain, turntable to transmitter, then back through the mod monitor to the Magnecord on which it was recorded was not only (of course) analog but TUBE-TYPE. It blows away anything you'd hear today, analog, digital, mono or stereo on AM.

Then mount an industry-wide push for "The New AM Radio - have you listened lately?"

No expensive, trouble-prone new receivers necessary. No preposterous phase-rotators for directional systems. Less sideband trouble. Almost total compatibility with existing radios. No bitter recriminations and divisiveness on industry blogs. Peace, harmony, and better sound.

Of course, it won't be DIGITAL. I figure that will be a problem for....oh, about 14 potential new listeners. And of course Ibiquity won't be able to extort annual licensing fees but....well.....what's that phrase I hear applied to my station, my livelihood, by IBOCers? "Sometimes evolutionary change is PAINFUL......"