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MAXIMUM AM FIDELITY-Copy of letter to the editor.

S

SuperSound

Friday, December 09, 2005

AM RADIO CUTS ALREADY POOR FIDELITY IN HALF!
LOOSING LISTENERS TO FM, AM RADIO HAS DECIDED THE ANSWER IS TO SOUND WORSE!
Dear Radio World Editor,
I strongly disagree with the conclusions drawn in the article "5 kHz Bandwidth Restriction suits AM" by George W. Woodard, PE, Dec. 7, 2005 Radio World.
This article not posted to web-No link yet available.
The conclusions he reached are not supported by his own data, and is contrary to the bulk of over 100 years of acoustic, medical, and electronic research.
His data and text show a -16 dB loss on his "Best" tested radio. At about 9000 Hz (NRSC-1 and 2 dictate high frequency pre-emphasis and a 10, 000 Hz cutoff) for broadcast AM. When the preemphasis that he mentions is included, this is reduced to about -6dB. NOT BAD! I'll settle for that.
Then he proposes that broadcast AM would sound better and more intelligible if the fidelity were cut in half to 5 kHz with a "brick wall" filter. Perhaps on short wave communication where sky wave with selective fading and selective sideband cancellation occur this might be an advantage. In AM broadcast where the primary coverage is ground wave, such effects are minimal.
Almost all acoustic, medical, electronic, speech, and other research strongly show higher fidelity, greater signal to noise, lower distortion, improve natural sound and intelligibility. The research for this is compellingly conclusive. If you have any doubt, study the research or ask any competent audiologist, medical doctor, acoustic engineer, or other professional.
The link below is to a recent white paper showing that speech intelligibility is increased with better response up to 14 kHz and there is a very significant loss of intelligibility when frequencies between 5 and 9 kHz are missing. (See Figure 2).
http://www.polycom.com/common/pw_cmp_updateDocKeywords/0,1687,1809,00.pdf
Add to this the very loud hiss created by HD radio-IBOC-iBiquity and AM radio is destroying itself. The level of the IBOC hiss belies it's actual loudness and loss of intelligibility because of the nature of the digital waveform vs. analog waveform. Square waves are much louder then sine waves of the same level. In addition, with most common radio detectors it is almost impossible to completely tune out this annoying and distracting digital hiss.
FM IBOC takes about 5 channels and is jamming favorite nearby stations in populated metropolitan areas, where most listeners live. It does not take a genius to divide by 5 the 100 available FM channels to see that about 20 unjammed channels is about the most you can expect in congested metropolitan areas. (4 of those channels are likely to fall in the non-commercial low end of the dial leaving only about 16 commercial FM stations).
The most favorable projections only predict that perhaps 10% of listeners will purchase HD radios in the next 5 years. Can broadcasting as we know it survive with less then 10% of it's current listeners?
HD radio is an expensive, destuctive hoax.
Sincerely,
Richard Franklin
HD RADIO=DIGITAL DISASTER!
http://worldsupercaster.blogspot.com
 
> Friday, December 09, 2005
>
> AM RADIO CUTS ALREADY POOR FIDELITY IN HALF!
> LOOSING LISTENERS TO FM, AM RADIO HAS DECIDED THE ANSWER IS
> TO SOUND WORSE!
> Dear Radio World Editor,
> I strongly disagree with the conclusions drawn in the
> article "5 kHz Bandwidth Restriction suits AM" by George W.
> Woodard, PE, Dec. 7, 2005 Radio World.
> This article not posted to web-No link yet available.
> The conclusions he reached are not supported by his own
> data, and is contrary to the bulk of over 100 years of
> acoustic, medical, and electronic research.
> His data and text show a -16 dB loss on his "Best" tested
> radio. At about 9000 Hz (NRSC-1 and 2 dictate high frequency
> pre-emphasis and a 10, 000 Hz cutoff) for broadcast AM. When
> the preemphasis that he mentions is included, this is
> reduced to about -6dB. NOT BAD! I'll settle for that.
> Then he proposes that broadcast AM would sound better and
> more intelligible if the fidelity were cut in half to 5 kHz
> with a "brick wall" filter. Perhaps on short wave
> communication where sky wave with selective fading and
> selective sideband cancellation occur this might be an
> advantage. In AM broadcast where the primary coverage is
> ground wave, such effects are minimal.
> Almost all acoustic, medical, electronic, speech, and other
> research strongly show higher fidelity, greater signal to
> noise, lower distortion, improve natural sound and
> intelligibility. The research for this is compellingly
> conclusive. If you have any doubt, study the research or ask
> any competent audiologist, medical doctor, acoustic
> engineer, or other professional.
> The link below is to a recent white paper showing that
> speech intelligibility is increased with better response up
> to 14 kHz and there is a very significant loss of
> intelligibility when frequencies between 5 and 9 kHz are
> missing. (See Figure 2).
http://www.po> lycom.com/common/pw_cmp_updateDocKeywords/0,1687,1809,00.pdf
>
> Add to this the very loud hiss created by HD
> radio-IBOC-iBiquity and AM radio is destroying itself. The
> level of the IBOC hiss belies it's actual loudness and loss
> of intelligibility because of the nature of the digital
> waveform vs. analog waveform. Square waves are much louder
> then sine waves of the same level. In addition, with most
> common radio detectors it is almost impossible to completely
> tune out this annoying and distracting digital hiss.
> FM IBOC takes about 5 channels and is jamming favorite
> nearby stations in populated metropolitan areas, where most
> listeners live. It does not take a genius to divide by 5 the
> 100 available FM channels to see that about 20 unjammed
> channels is about the most you can expect in congested
> metropolitan areas. (4 of those channels are likely to fall
> in the non-commercial low end of the dial leaving only about
> 16 commercial FM stations).
> The most favorable projections only predict that perhaps 10%
> of listeners will purchase HD radios in the next 5 years.
> Can broadcasting as we know it survive with less then 10% of
> it's current listeners?
> HD radio is an expensive, destuctive hoax.
> Sincerely,
> Richard Franklin
> HD RADIO=DIGITAL DISASTER!
> http://worldsupercaster.blogspot.com
>
Ma Bell did extensive research on frequency response and it's relationship to intelligibility. Mama says, and she is very smart, that 300-3000 Hz response is the bare minimum for speech. Additional bandwith is just not needed for "intelligibility."
Now....does 10 khz (or 15 Khz) SOUND better? Why, of course! But can the average AM radio reproduce anything above 3 Khz? No! Why waste transmitter energy on spectrum which can't be heard by 99.99% of the listeners?
I agree with the folks who think IBOC is not a mature technology. It seems that the AM "hybrid mode" technology is hopelessly flawed for night service. It is time for other "different" ideas.....but AM stereo is not the answer.
I hear Leonard Kahn is perfecting a digital sparkgap AM transmission system....wonder if you will have to have two radios to decode it?
 
typo

> Friday, December 09, 2005
>
> AM RADIO CUTS ALREADY POOR FIDELITY IN HALF!
> LOOSING LISTENERS TO FM, AM RADIO HAS DECIDED THE ANSWER IS
> TO SOUND WORSE!

Before I even read your letter, if you want it to be taken seriously, please fix the spelling mistake in your title. The correct word is "LOSING".

Remember: LOOSE LIPS LOSE SHIPS
<P ID="signature">______________
ImportantInfo.jpg

"This is the New York Emergency Broadcast System satellite channel. They took the crosstown bus."</P>
 
>Why waste transmitter energy on spectrum which can't be heard by 99.99% of the listeners?<

Why have AM at all, considering how few people tune in because of poor fidelity?
 
> >Why waste transmitter energy on spectrum which can't be
> heard by 99.99% of the listeners?<
>
> Why have AM at all, considering how few people tune in
> because of poor fidelity?
>
AM is a great medium for Talk radio, and serves that purpose well. But you are right, it has poor fidelity for music.

I believe the #2 and #3 highest rated stations in Chicago are both AM stations. So I guess someone is listening to AM...

Dr. Dave
 
> > Why have AM at all, considering how few people tune in
> > because of poor fidelity?
> >

So, fix the fidelity. I've heard AM stations that rvial FM in sound quality...but that was many years ago. Unfortunately with the relaxation of power line and comsumer device interference rules, and the systematic missteps in AM 'technology' it's probably too late.

<P ID="signature">______________
Never hold a cat and a dustbuster at the same time.</P>
 
This post was duplicated on the FCC board... I closed that thread and posted a link to this one since there were no comments on that post.

-A

(Mod, FCC board)<P ID="signature">______________

</P>
 
> So, fix the fidelity. I've heard AM stations that rvial FM
> in sound quality...but that was many years ago.
> Unfortunately with the relaxation of power line and comsumer
> device interference rules, and the systematic missteps in AM
> 'technology' it's probably too late.
>

"Fixing" AM fidelity is like building a better buggy whip. 30 years ago the public was convinced that AM sounded lousy...do you really think you're gonna undo that? Yes there were (and are) good sounding AM stations, but there's zero demand for good sounding AM radios. Perception is reality.

As someone else mentioned, there are still AM stations that are going strong...almost all of them have flamethrower signals and news/talk formats. I wonder how some of the smaller stations with crummy signals hang on.
 
AM radio response - above 3 Khz?

.
.
> But can the average AM radio reproduce anything above 3 Khz? No!

A deeply, flawed, unsupportable assertion standing in contradiction to ongoing experiences even now.

To wit, the horridly narrow sounding 4.5 KHz response of KMKI in my market compared to the 6 KHz or so wide audio response of KRLD.

You need ONLY go back about 7 months to see the freq response postings I made of KRLD and KMKI and then experience with a variety of radios the 'human' perception aspect of said limited audio of KMKI versus the wider response of KRLD.
 
> > > Why have AM at all, considering how few people tune in
> > > because of poor fidelity?
> > >
>
> So, fix the fidelity. I've heard AM stations that rvial FM
> in sound quality...but that was many years ago.
> Unfortunately with the relaxation of power line and comsumer
> device interference rules, and the systematic missteps in AM
> 'technology' it's probably too late.
>

Fixing the fidelity is more a factor of the receivers than the transmitters. IMHO the broadcasters have thrown their hands up in the air and say I GIVE UP. They should not have doen that but instead should have worked more with the reciver manufacturers at making decent receivers.
 
> Fixing the fidelity is more a factor of the receivers than
> the transmitters. IMHO the broadcasters have thrown their
> hands up in the air and say I GIVE UP. They should not have
> doen that but instead should have worked more with the
> reciver manufacturers at making decent receivers.
>

The time to have done that would have been 30+ years ago when AM was still semi-viable as a music medium. Alas, there is ZERO consumer demand for better-sounding AM radios. I feel bad for AM broadcasters who make the effort to make their stations sound good...few if any listeners notice or care. The public is convinced it's the stations that sound bad, not the radio (after all the same radio sounds just fine on FM, so it can't be the radio, right?).
 
> > Fixing the fidelity is more a factor of the receivers than
>
> > the transmitters. IMHO the broadcasters have thrown their
>
> > hands up in the air and say I GIVE UP. They should not
> have
> > doen that but instead should have worked more with the
> > reciver manufacturers at making decent receivers.
> >
>
> The time to have done that would have been 30+ years ago
> when AM was still semi-viable as a music medium. Alas,
> there is ZERO consumer demand for better-sounding AM radios.
> I feel bad for AM broadcasters who make the effort to make
> their stations sound good...few if any listeners notice or
> care. The public is convinced it's the stations that sound
> bad, not the radio (after all the same radio sounds just
> fine on FM, so it can't be the radio, right?).
>

I beg to differ. We have a number of people that write into our AM music station thanking us for the decent sound. It also does fairly well in the market beating out a number of full power FM stations.
 
> I beg to differ. We have a number of people that write into
> our AM music station thanking us for the decent sound. It
> also does fairly well in the market beating out a number of
> full power FM stations.
>

If true, your station is the exception, not the rule. How many successful AM music stations can you name? There can't be more than a handful, mostly in smaller markets. While there is no excuse for crappy sound on-air, the fault usually lies in the receiver. This has been the sad reality for 30+ years.
 
> > I beg to differ. We have a number of people that write
> into
> > our AM music station thanking us for the decent sound. It
>
> > also does fairly well in the market beating out a number
> of
> > full power FM stations.
> >
>
> If true, your station is the exception, not the rule. How
> many successful AM music stations can you name? There can't
> be more than a handful, mostly in smaller markets. While
> there is no excuse for crappy sound on-air, the fault
> usually lies in the receiver. This has been the sad reality
> for 30+ years.
>

There are a bunch of music formats working on AM, mostly skewing older such as oldies, and Music of Your Life...

Oh, yes, there's also WSM.

But I agree with the comments about the receivers. It would have to be improved from both sides.



<P ID="signature">______________
Never hold a cat and a dustbuster at the same time.</P>
 
> Ma Bell did extensive research on frequency response and
> it's relationship to intelligibility. Mama says, and she is
> very smart, that 300-3000 Hz response is the bare minimum
> for speech. Additional bandwith is just not needed for
> "intelligibility."
> Now....does 10 khz (or 15 Khz) SOUND better? Why, of course!
> But can the average AM radio reproduce anything above 3 Khz?
> No! Why waste transmitter energy on spectrum which can't be
> heard by 99.99% of the listeners?
>

This is purely anecdotal...but amusing nonetheless...

In Boston, WEEI 850AM carries the Red Sox games. A rimshot Class A FM, WBOQ 104.9, simulcasts them. Now I don't know how WBOQ gets the audio from WEEI, but it's not OTA because the frequency response is obviously (to my ears) much wider. I'm guessing ISDN b/c there's almost no delay between the two, so it can't be a webcast.

Anyways, what's amusing is this: I live in an area where both stations come in strong. And to my ears, the WEEI broadcast sounds MUCH better. WBOQ's sounds harsh and brittle; whereas WEEI sounds warm with plenty of "oomph". The crowd sounds aren't as obnoxious on WEEI either.

I don't know if WEEI throttles their bandwidth to the IBOC-required 5kHz. I know they don't have IBOC installed yet and I doubt they will anytime soon; most Red Sox games start at 7:05pm...well after the required 6pm IBOC shutoff time...so why bother? Still, if I had to guess I'd say they're not far from the 5kHz throttle...that audio sounds pretty lacking in high end (with gobs of processing to make up for it, I might add :)

I'm sure the reason WBOQ "sounds worse" is that they're not changing their processing to compensate from their normal music programming, but I just thought it was funny.

BTW, I agree that AM IBOC has way too many question marks attached to it for anyone to consider it a real "solution". But the pols in Washington have made it clear that new spectrum is far too valuable at two-way communication auctions to be allocated in a giveaway to one-way broadcasters...so forget about Eureka147. And the mess that is the DTV transition implies that a massive switchover system, like Digital Radio Mondiale, is probably not a good idea either.

I fear the only solution may be something of a "final solution" where several smaller AM broadcasters are forced to go dark. (Hey the FCC has done it before! Granted it was about 80 years ago... :)

One wonders if that happens, will the FCC will force FM broadcasters to allocate some multicast channels to displaced AM broadcasters? What a weird world that would be...
 
Re: typo-Reply

> > Friday, December 09, 2005
> >
> > AM RADIO CUTS ALREADY POOR FIDELITY IN HALF!
> > LOOSING LISTENERS TO FM, AM RADIO HAS DECIDED THE ANSWER
> IS
> > TO SOUND WORSE!
>
> Before I even read your letter, if you want it to be taken
> seriously, please fix the spelling mistake in your title.
> The correct word is "LOSING".
>
> Remember: LOOSE LIPS LOSE SHIPS
>
If a single typo upsets you that much, perhaps you should give up reading.
-Rich
P. S. -A nervous breakdown:
etekletpneertyuiopfghjknvcxz!
 
Ma Bell never claimed 300-3000 Hz was optimal for speech. It was just a minimal standard bandwidth for economical long line transmission. "Intelligibility is enhanced with bandwidth" Ma Bell said.
Here is the link references, experimental evidence, and proof:
http://www.polycom.com/common/pw_cmp_updateDocKeywords/0,1687,1809,00.pdf

In fact Western Electic labs (Ma Bell's research and equipment manufacturer) did much of the early research on high fidelity!!! Western Electric also manufactured high fidelity audio and transmission equipment. Their AM transmitters and professional audio gear were among the first to promote high fidelity broadcasting as a benefit.
AM radios are not limited to 3 Khz, and with NRSC-1 and 2 pre-emphasis can extend to 9 Khz.
Who said anything about AM stereo?
It's a dead duck, just as iBiquity-HD Radio-NRSC-5 is a "Dead Man Walking".
If 99.99% of the listeners can't hear above 3 Khz, why change anything to digital?
What is the two radios business about?
Nothing that I said.
Spark gap was Marconi, I beleve.



> > Friday, December 09, 2005
> >
> > AM RADIO CUTS ALREADY POOR FIDELITY IN HALF!
> > LOOSING LISTENERS TO FM, AM RADIO HAS DECIDED THE ANSWER
> IS
> > TO SOUND WORSE!
> > Dear Radio World Editor,
> > I strongly disagree with the conclusions drawn in the
> > article "5 kHz Bandwidth Restriction suits AM" by George
> W.
> > Woodard, PE, Dec. 7, 2005 Radio World.
> > This article not posted to web-No link yet available.
> > The conclusions he reached are not supported by his own
> > data, and is contrary to the bulk of over 100 years of
> > acoustic, medical, and electronic research.
> > His data and text show a -16 dB loss on his "Best" tested
> > radio. At about 9000 Hz (NRSC-1 and 2 dictate high
> frequency
> > pre-emphasis and a 10, 000 Hz cutoff) for broadcast AM.
> When
> > the preemphasis that he mentions is included, this is
> > reduced to about -6dB. NOT BAD! I'll settle for that.
> > Then he proposes that broadcast AM would sound better and
> > more intelligible if the fidelity were cut in half to 5
> kHz
> > with a "brick wall" filter. Perhaps on short wave
> > communication where sky wave with selective fading and
> > selective sideband cancellation occur this might be an
> > advantage. In AM broadcast where the primary coverage is
> > ground wave, such effects are minimal.
> > Almost all acoustic, medical, electronic, speech, and
> other
> > research strongly show higher fidelity, greater signal to
> > noise, lower distortion, improve natural sound and
> > intelligibility. The research for this is compellingly
> > conclusive. If you have any doubt, study the research or
> ask
> > any competent audiologist, medical doctor, acoustic
> > engineer, or other professional.
> > The link below is to a recent white paper showing that
> > speech intelligibility is increased with better response
> up
> > to 14 kHz and there is a very significant loss of
> > intelligibility when frequencies between 5 and 9 kHz are
> > missing. (See Figure 2).
> http://www.po>
> lycom.com/common/pw_cmp_updateDocKeywords/0,1687,1809,00.pdf
>
> >
> > Add to this the very loud hiss created by HD
> > radio-IBOC-iBiquity and AM radio is destroying itself. The
>
> > level of the IBOC hiss belies it's actual loudness and
> loss
> > of intelligibility because of the nature of the digital
> > waveform vs. analog waveform. Square waves are much louder
>
> > then sine waves of the same level. In addition, with most
> > common radio detectors it is almost impossible to
> completely
> > tune out this annoying and distracting digital hiss.
> > FM IBOC takes about 5 channels and is jamming favorite
> > nearby stations in populated metropolitan areas, where
> most
> > listeners live. It does not take a genius to divide by 5
> the
> > 100 available FM channels to see that about 20 unjammed
> > channels is about the most you can expect in congested
> > metropolitan areas. (4 of those channels are likely to
> fall
> > in the non-commercial low end of the dial leaving only
> about
> > 16 commercial FM stations).
> > The most favorable projections only predict that perhaps
> 10%
> > of listeners will purchase HD radios in the next 5 years.
> > Can broadcasting as we know it survive with less then 10%
> of
> > it's current listeners?
> > HD radio is an expensive, destuctive hoax.
> > Sincerely,
> > Richard Franklin
> > HD RADIO=DIGITAL DISASTER!
> > http://worldsupercaster.blogspot.com
> >
> Ma Bell did extensive research on frequency response and
> it's relationship to intelligibility. Mama says, and she is
> very smart, that 300-3000 Hz response is the bare minimum
> for speech. Additional bandwith is just not needed for
> "intelligibility."
> Now....does 10 khz (or 15 Khz) SOUND better? Why, of course!
> But can the average AM radio reproduce anything above 3 Khz?
> No! Why waste transmitter energy on spectrum which can't be
> heard by 99.99% of the listeners?
> I agree with the folks who think IBOC is not a mature
> technology. It seems that the AM "hybrid mode" technology is
> hopelessly flawed for night service. It is time for other
> "different" ideas.....but AM stereo is not the answer.
> I hear Leonard Kahn is perfecting a digital sparkgap AM
> transmission system....wonder if you will have to have two
> radios to decode it?
>
 
> Ma Bell never claimed 300-3000 Hz was optimal for speech. It
> was just a minimal standard bandwidth for economical long
> line transmission. "Intelligibility is enhanced with
> bandwidth" Ma Bell said.
> Here is the link references, experimental evidence, and
> proof:
http://www.po> lycom.com/common/pw_cmp_updateDocKeywords/0,1687,1809,00.pdf
>
>
> In fact Western Electic labs (Ma Bell's research and
> equipment manufacturer) did much of the early research on
> high fidelity!!! Western Electric also manufactured high
> fidelity audio and transmission equipment. Their AM
> transmitters and professional audio gear were among the
> first to promote high fidelity broadcasting as a benefit.
> AM radios are not limited to 3 Khz, and with NRSC-1 and 2
> pre-emphasis can extend to 9 Khz.
> Who said anything about AM stereo?
> It's a dead duck, just as iBiquity-HD Radio-NRSC-5 is a
> "Dead Man Walking".
> If 99.99% of the listeners can't hear above 3 Khz, why
> change anything to digital?
> What is the two radios business about?
> Nothing that I said.
> Spark gap was Marconi, I beleve.
>
> I do not dispute the value of additional freq response.....it's like adding additional sampling of a waveform.....more bits, more resolution. But there is a point where the "quality" increases become negligible.
You must not remember Kahn's AM stereo scheme....the stereo could be heard with 2 mono radios, each tuned to the side of carrier.The stereo image was created by using the upper and lower sidebands to carry left and right channels.

The sparkgap mention was a feeble attempt at humour....please excuse!!

My only point was/is: with AM in it's present state, why do you care if bandwith is restricted? Can you not understand what's being said on any ClearChannel news/talk station? If so, then I suggest a hearing test with your local ENT.Yes, it would sound "better" with additional freq response....but it is intelligible!
When CBS did the famous audio research back in the sixties, which led to the infamous
Volumax" audio processors, they found people were most bothered by NOISE! Not mono, not processing, but good ol' noise. The best thing we, as an industry, could do to "fix" AM is to, as mentioned below, cull out the AM band and reduce interference,and create *effective* noise suppression.
I personally think the old "narrow band FM" experimented with in the 70's and 80's is worth a re-vist.It would only be mono, but it would have much less NOISE!
>
> > > Friday, December 09, 2005
> > >
> > > AM RADIO CUTS ALREADY POOR FIDELITY IN HALF!
> > > LOOSING LISTENERS TO FM, AM RADIO HAS DECIDED THE ANSWER
>
> > IS
> > > TO SOUND WORSE!
> > > Dear Radio World Editor,
> > > I strongly disagree with the conclusions drawn in the
> > > article "5 kHz Bandwidth Restriction suits AM" by George
>
> > W.
> > > Woodard, PE, Dec. 7, 2005 Radio World.
> > > This article not posted to web-No link yet available.
> > > The conclusions he reached are not supported by his own
> > > data, and is contrary to the bulk of over 100 years of
> > > acoustic, medical, and electronic research.
> > > His data and text show a -16 dB loss on his "Best"
> tested
> > > radio. At about 9000 Hz (NRSC-1 and 2 dictate high
> > frequency
> > > pre-emphasis and a 10, 000 Hz cutoff) for broadcast AM.
> > When
> > > the preemphasis that he mentions is included, this is
> > > reduced to about -6dB. NOT BAD! I'll settle for that.
> > > Then he proposes that broadcast AM would sound better
> and
> > > more intelligible if the fidelity were cut in half to 5
> > kHz
> > > with a "brick wall" filter. Perhaps on short wave
> > > communication where sky wave with selective fading and
> > > selective sideband cancellation occur this might be an
> > > advantage. In AM broadcast where the primary coverage is
>
> > > ground wave, such effects are minimal.
> > > Almost all acoustic, medical, electronic, speech, and
> > other
> > > research strongly show higher fidelity, greater signal
> to
> > > noise, lower distortion, improve natural sound and
> > > intelligibility. The research for this is compellingly
> > > conclusive. If you have any doubt, study the research or
>
> > ask
> > > any competent audiologist, medical doctor, acoustic
> > > engineer, or other professional.
> > > The link below is to a recent white paper showing that
> > > speech intelligibility is increased with better response
>
> > up
> > > to 14 kHz and there is a very significant loss of
> > > intelligibility when frequencies between 5 and 9 kHz are
>
> > > missing. (See Figure 2).
> > http://www.po>
> >
> lycom.com/common/pw_cmp_updateDocKeywords/0,1687,1809,00.pdf
>
> >
> > >
> > > Add to this the very loud hiss created by HD
> > > radio-IBOC-iBiquity and AM radio is destroying itself.
> The
> >
> > > level of the IBOC hiss belies it's actual loudness and
> > loss
> > > of intelligibility because of the nature of the digital
> > > waveform vs. analog waveform. Square waves are much
> louder
> >
> > > then sine waves of the same level. In addition, with
> most
> > > common radio detectors it is almost impossible to
> > completely
> > > tune out this annoying and distracting digital hiss.
> > > FM IBOC takes about 5 channels and is jamming favorite
> > > nearby stations in populated metropolitan areas, where
> > most
> > > listeners live. It does not take a genius to divide by 5
>
> > the
> > > 100 available FM channels to see that about 20 unjammed
> > > channels is about the most you can expect in congested
> > > metropolitan areas. (4 of those channels are likely to
> > fall
> > > in the non-commercial low end of the dial leaving only
> > about
> > > 16 commercial FM stations).
> > > The most favorable projections only predict that perhaps
>
> > 10%
> > > of listeners will purchase HD radios in the next 5
> years.
> > > Can broadcasting as we know it survive with less then
> 10%
> > of
> > > it's current listeners?
> > > HD radio is an expensive, destuctive hoax.
> > > Sincerely,
> > > Richard Franklin
> > > HD RADIO=DIGITAL DISASTER!
> > > http://worldsupercaster.blogspot.com
> > >
> > Ma Bell did extensive research on frequency response and
> > it's relationship to intelligibility. Mama says, and she
> is
> > very smart, that 300-3000 Hz response is the bare minimum
> > for speech. Additional bandwith is just not needed for
> > "intelligibility."
> > Now....does 10 khz (or 15 Khz) SOUND better? Why, of
> course!
> > But can the average AM radio reproduce anything above 3
> Khz?
> > No! Why waste transmitter energy on spectrum which can't
> be
> > heard by 99.99% of the listeners?
> > I agree with the folks who think IBOC is not a mature
> > technology. It seems that the AM "hybrid mode" technology
> is
> > hopelessly flawed for night service. It is time for other
> > "different" ideas.....but AM stereo is not the answer.
> > I hear Leonard Kahn is perfecting a digital sparkgap AM
> > transmission system....wonder if you will have to have two
>
> > radios to decode it?
> >
>
 
Re: MAXIMUM AM FIDELITY-Rich's reply.

HD digital radio hiss causes more noise, not less, on the over 800 million radios in the USA.

The loud hiss on analog radios caused by HD digital radio decreases signal to noise ratio, intelligibility, and can't be completely tuned out by most analog radios. In addition, as more stations join the digital lemmings, the hiss will spread accross the entire medium wave broadcast band, jamming more stations, and further reducing intelligibility.

The link below is to a recent white paper showing that speech intelligibility is almost doubled with better response up to 14 kHz and there is a very significant loss of intelligibility (40%) when frequencies between 5 and 9 kHz are missing. (See Figure 2).

http://www.polycom.com/common/pw_cmp_updateDocKeywords/0,1687,1809,00.pdf

This research disproves your point about limited bandwith increasing intelligability.

Clear channel stations are getting much less clear with a 5 kHz brick wall filter. Complaints about the digital hiss, plus muffled, unnatural and "phasey" sound from the 5 kHz brick wall filter are mounting.

AM radio bandwith is often much better then you claim in your statements, and is enhanced by the high frequency 10db preemphsis required by NRSC-1 and NRSC-2. Some AM radios test only 6 db down at 9 kHz with the transmission preemphasis enabled. Not bad!

More details about this is posted on my blog: http://worldsupercaster.blogspot.com

Narrow band FM was tested on medium wave (about 25 years ago) with disappointing results. Most of the increase in signal to noise by using FM was determined to be due to the increased modulation of wideband FM. A single wideband FM signal on the medium wave broadcast band would take up 16 AM broadcast channels for one wideband FM medium wave broadcast station.

The interferance and jamming are bad with HD digital FM too, Jamming popular suburban stations, LPFM's and translators.

HD digital radio is a digital disaster. The NRSC-5, iBiquity digital system is seriously flawed, and should not be allowed.

HD digital radio is defective, and incompatable with analog AM or FM.

-Rich


> > Ma Bell never claimed 300-3000 Hz was optimal for speech.
> It
> > was just a minimal standard bandwidth for economical long
> > line transmission. "Intelligibility is enhanced with
> > bandwidth" Ma Bell said.
> > Here is the link references, experimental evidence, and
> > proof:
> http://www.po>
> lycom.com/common/pw_cmp_updateDocKeywords/0,1687,1809,00.pdf
>
> >
> >
> > In fact Western Electic labs (Ma Bell's research and
> > equipment manufacturer) did much of the early research on
> > high fidelity!!! Western Electric also manufactured high
> > fidelity audio and transmission equipment. Their AM
> > transmitters and professional audio gear were among the
> > first to promote high fidelity broadcasting as a benefit.
> > AM radios are not limited to 3 Khz, and with NRSC-1 and 2
> > pre-emphasis can extend to 9 Khz.
> > Who said anything about AM stereo?
> > It's a dead duck, just as iBiquity-HD Radio-NRSC-5 is a
> > "Dead Man Walking".
> > If 99.99% of the listeners can't hear above 3 Khz, why
> > change anything to digital?
> > What is the two radios business about?
> > Nothing that I said.
> > Spark gap was Marconi, I beleve.
> >
> > I do not dispute the value of additional freq
> response.....it's like adding additional sampling of a
> waveform.....more bits, more resolution. But there is a
> point where the "quality" increases become negligible.
> You must not remember Kahn's AM stereo scheme....the stereo
> could be heard with 2 mono radios, each tuned to the side of
> carrier.The stereo image was created by using the upper and
> lower sidebands to carry left and right channels.
>
> The sparkgap mention was a feeble attempt at
> humour....please excuse!!
>
> My only point was/is: with AM in it's present state, why do
> you care if bandwith is restricted? Can you not understand
> what's being said on any ClearChannel news/talk station? If
> so, then I suggest a hearing test with your local ENT.Yes,
> it would sound "better" with additional freq response....but
> it is intelligible!
> When CBS did the famous audio research back in the sixties,
> which led to the infamous
> Volumax" audio processors, they found people were most
> bothered by NOISE! Not mono, not processing, but good ol'
> noise. The best thing we, as an industry, could do to "fix"
> AM is to, as mentioned below, cull out the AM band and
> reduce interference,and create *effective* noise
> suppression.
> I personally think the old "narrow band FM" experimented
> with in the 70's and 80's is worth a re-vist.It would only
> be mono, but it would have much less NOISE!
> >
> > > > Friday, December 09, 2005
> > > >
> > > > AM RADIO CUTS ALREADY POOR FIDELITY IN HALF!
> > > > LOOSING LISTENERS TO FM, AM RADIO HAS DECIDED THE
> ANSWER
> >
> > > IS
> > > > TO SOUND WORSE!
> > > > Dear Radio World Editor,
> > > > I strongly disagree with the conclusions drawn in the
> > > > article "5 kHz Bandwidth Restriction suits AM" by
> George
> >
> > > W.
> > > > Woodard, PE, Dec. 7, 2005 Radio World.
> > > > This article not posted to web-No link yet available.
> > > > The conclusions he reached are not supported by his
> own
> > > > data, and is contrary to the bulk of over 100 years of
>
> > > > acoustic, medical, and electronic research.
> > > > His data and text show a -16 dB loss on his "Best"
> > tested
> > > > radio. At about 9000 Hz (NRSC-1 and 2 dictate high
> > > frequency
> > > > pre-emphasis and a 10, 000 Hz cutoff) for broadcast
> AM.
> > > When
> > > > the preemphasis that he mentions is included, this is
> > > > reduced to about -6dB. NOT BAD! I'll settle for that.
> > > > Then he proposes that broadcast AM would sound better
> > and
> > > > more intelligible if the fidelity were cut in half to
> 5
> > > kHz
> > > > with a "brick wall" filter. Perhaps on short wave
> > > > communication where sky wave with selective fading and
>
> > > > selective sideband cancellation occur this might be an
>
> > > > advantage. In AM broadcast where the primary coverage
> is
> >
> > > > ground wave, such effects are minimal.
> > > > Almost all acoustic, medical, electronic, speech, and
> > > other
> > > > research strongly show higher fidelity, greater signal
>
> > to
> > > > noise, lower distortion, improve natural sound and
> > > > intelligibility. The research for this is compellingly
>
> > > > conclusive. If you have any doubt, study the research
> or
> >
> > > ask
> > > > any competent audiologist, medical doctor, acoustic
> > > > engineer, or other professional.
> > > > The link below is to a recent white paper showing that
>
> > > > speech intelligibility is increased with better
> response
> >
> > > up
> > > > to 14 kHz and there is a very significant loss of
> > > > intelligibility when frequencies between 5 and 9 kHz
> are
> >
> > > > missing. (See Figure 2).
> > > http://www.po>
> > >
> >
> lycom.com/common/pw_cmp_updateDocKeywords/0,1687,1809,00.pdf
>
> >
> > >
> > > >
> > > > Add to this the very loud hiss created by HD
> > > > radio-IBOC-iBiquity and AM radio is destroying itself.
>
> > The
> > >
> > > > level of the IBOC hiss belies it's actual loudness and
>
> > > loss
> > > > of intelligibility because of the nature of the
> digital
> > > > waveform vs. analog waveform. Square waves are much
> > louder
> > >
> > > > then sine waves of the same level. In addition, with
> > most
> > > > common radio detectors it is almost impossible to
> > > completely
> > > > tune out this annoying and distracting digital hiss.
> > > > FM IBOC takes about 5 channels and is jamming favorite
>
> > > > nearby stations in populated metropolitan areas, where
>
> > > most
> > > > listeners live. It does not take a genius to divide by
> 5
> >
> > > the
> > > > 100 available FM channels to see that about 20
> unjammed
> > > > channels is about the most you can expect in congested
>
> > > > metropolitan areas. (4 of those channels are likely to
>
> > > fall
> > > > in the non-commercial low end of the dial leaving only
>
> > > about
> > > > 16 commercial FM stations).
> > > > The most favorable projections only predict that
> perhaps
> >
> > > 10%
> > > > of listeners will purchase HD radios in the next 5
> > years.
> > > > Can broadcasting as we know it survive with less then
> > 10%
> > > of
> > > > it's current listeners?
> > > > HD radio is an expensive, destuctive hoax.
> > > > Sincerely,
> > > > Richard Franklin
> > > > HD RADIO=DIGITAL DISASTER!
> > > > http://worldsupercaster.blogspot.com
> > > >
> > > Ma Bell did extensive research on frequency response and
>
> > > it's relationship to intelligibility. Mama says, and she
>
> > is
> > > very smart, that 300-3000 Hz response is the bare
> minimum
> > > for speech. Additional bandwith is just not needed for
> > > "intelligibility."
> > > Now....does 10 khz (or 15 Khz) SOUND better? Why, of
> > course!
> > > But can the average AM radio reproduce anything above 3
> > Khz?
> > > No! Why waste transmitter energy on spectrum which
> can't
> > be
> > > heard by 99.99% of the listeners?
> > > I agree with the folks who think IBOC is not a mature
> > > technology. It seems that the AM "hybrid mode"
> technology
> > is
> > > hopelessly flawed for night service. It is time for
> other
> > > "different" ideas.....but AM stereo is not the answer.
> > > I hear Leonard Kahn is perfecting a digital sparkgap AM
> > > transmission system....wonder if you will have to have
> two
> >
> > > radios to decode it?
> > >
> >
>
 
Re: MAXIMUM AM FIDELITY-Rich's reply.

> HD digital radio hiss causes more noise, not less, on the
> over 800 million radios in the USA.
>
> The loud hiss on analog radios caused by HD digital radio
> decreases signal to noise ratio, intelligibility, and can't
> be completely tuned out by most analog radios. In addition,
> as more stations join the digital lemmings, the hiss will
> spread accross the entire medium wave broadcast band,
> jamming more stations, and further reducing intelligibility.
>
>
> The link below is to a recent white paper showing that
> speech intelligibility is almost doubled with better
> response up to 14 kHz and there is a very significant loss
> of intelligibility (40%) when frequencies between 5 and 9
> kHz are missing. (See Figure 2).
>
http://www.po> lycom.com/common/pw_cmp_updateDocKeywords/0,1687,1809,00.pdf
>
>
> This research disproves your point about limited bandwith
> increasing intelligability.


>
Huh?? That was NEVER my point! I never argued that REDUCING bandwith IMPROVED intelligibility! I simply said, phone bandwith is THE BARE MINIMUM for "good" intelligibility......that's all. And further, additional bandwith may improve intelligibility, but there is a point of diminishing return....how much bandwith is NECESSARY for REASONABLE intelligibility.
Has there ever been a word said on a ClearChannel N/T station you could not understand because of bandwith restriction? I listen to a CC news/talker every day and have no problem understanding every word spoken.
Did it sound better BEFORE the brickwall was installed....yes, it did!But I can also hear the adjacent channel,WSM's Grand Ol Opry, 3 miles from the transmitter, at night! That was one of the main benefits of the restriction and has helped night service in regard to adjacent channel splatter.
I said IBOC is NOT a mature technology.....I agree with your observations, and opinions regarding IBOC. Your point regarding adjacent channel interference from IBOC sidebands also argues for bandwith restrictions.....remember when stations were 15Khz? Splatter on adjacents.....even if(and that's a BIG if)the transmitter was tuned and operating correctly....for miles around EVERY station.You could not hear half the clear channels because the local station was"decorating the dial"for a couple of channels each side of carrier.


> Clear channel stations are getting much less clear with a 5
> kHz brick wall filter. Complaints about the digital hiss,
> plus muffled, unnatural and "phasey" sound from the 5 kHz
> brick wall filter are mounting.


But you can still understand every word spoken....right??

>
> AM radio bandwith is often much better then you claim in
> your statements, and is enhanced by the high frequency 10db
> preemphsis required by NRSC-1 and NRSC-2. Some AM radios
> test only 6 db down at 9 kHz with the transmission
> preemphasis enabled. Not bad!

You are 6DB down at 9KHZ and you think that's "not bad??" Your "sound" is not very "super" Rich!!
>
> More details about this is posted on my blog:
> http://worldsupercaster.blogspot.com
>
> Narrow band FM was tested on medium wave (about 25 years
> ago) with disappointing results. Most of the increase in
> signal to noise by using FM was determined to be due to the
> increased modulation of wideband FM. A single wideband FM
> signal on the medium wave broadcast band would take up 16 AM
> broadcast channels for one wideband FM medium wave broadcast
> station.
>
Wrong, sir!!
Most "noise" is amplitude modulated, by nature, and man made.The major gain is modulation technique, not bandwith!!
The technology never was accepted due to flaws inherent to narrow band FM....I agree with you on that. Can those problems be overcome? I'm not smart enough to opine on that one.....
We need a new and different approach to AM improvement. That's all I'm trying to say!
> The interferance and jamming are bad with HD digital FM too,
> Jamming popular suburban stations, LPFM's and translators.
>
> HD digital radio is a digital disaster. The NRSC-5, iBiquity
> digital system is seriously flawed, and should not be
> allowed.
>
> HD digital radio is defective, and incompatable with analog
> AM or FM.


> Agreed, on AM. What are the "incompatabilities" concerning FM?? There are numerous HD FM stations in my market.....I've heard NO artifacts added to their analog signals and NO interference to adjacent channels.


> -Rich
>
>
> > > Ma Bell never claimed 300-3000 Hz was optimal for
> speech.
> > It
> > > was just a minimal standard bandwidth for economical
> long
> > > line transmission. "Intelligibility is enhanced with
> > > bandwidth" Ma Bell said.
> > > Here is the link references, experimental evidence, and
> > > proof:
> > http://www.po>
> >
> lycom.com/common/pw_cmp_updateDocKeywords/0,1687,1809,00.pdf
>
> >
> > >
> > >
> > > In fact Western Electic labs (Ma Bell's research and
> > > equipment manufacturer) did much of the early research
> on
> > > high fidelity!!! Western Electric also manufactured high
>
> > > fidelity audio and transmission equipment. Their AM
> > > transmitters and professional audio gear were among the
> > > first to promote high fidelity broadcasting as a
> benefit.
> > > AM radios are not limited to 3 Khz, and with NRSC-1 and
> 2
> > > pre-emphasis can extend to 9 Khz.
> > > Who said anything about AM stereo?
> > > It's a dead duck, just as iBiquity-HD Radio-NRSC-5 is a
> > > "Dead Man Walking".
> > > If 99.99% of the listeners can't hear above 3 Khz, why
> > > change anything to digital?
> > > What is the two radios business about?
> > > Nothing that I said.
> > > Spark gap was Marconi, I beleve.
> > >
> > > I do not dispute the value of additional freq
> > response.....it's like adding additional sampling of a
> > waveform.....more bits, more resolution. But there is a
> > point where the "quality" increases become negligible.
> > You must not remember Kahn's AM stereo scheme....the
> stereo
> > could be heard with 2 mono radios, each tuned to the side
> of
> > carrier.The stereo image was created by using the upper
> and
> > lower sidebands to carry left and right channels.
> >
> > The sparkgap mention was a feeble attempt at
> > humour....please excuse!!
> >
> > My only point was/is: with AM in it's present state, why
> do
> > you care if bandwith is restricted? Can you not understand
>
> > what's being said on any ClearChannel news/talk station?
> If
> > so, then I suggest a hearing test with your local ENT.Yes,
>
> > it would sound "better" with additional freq
> response....but
> > it is intelligible!
> > When CBS did the famous audio research back in the
> sixties,
> > which led to the infamous
> > Volumax" audio processors, they found people were most
> > bothered by NOISE! Not mono, not processing, but good ol'
> > noise. The best thing we, as an industry, could do to
> "fix"
> > AM is to, as mentioned below, cull out the AM band and
> > reduce interference,and create *effective* noise
> > suppression.
> > I personally think the old "narrow band FM" experimented
> > with in the 70's and 80's is worth a re-vist.It would only
>
> > be mono, but it would have much less NOISE!
> > >
> > > > > Friday, December 09, 2005
> > > > >
> > > > > AM RADIO CUTS ALREADY POOR FIDELITY IN HALF!
> > > > > LOOSING LISTENERS TO FM, AM RADIO HAS DECIDED THE
> > ANSWER
> > >
> > > > IS
> > > > > TO SOUND WORSE!
> > > > > Dear Radio World Editor,
> > > > > I strongly disagree with the conclusions drawn in
> the
> > > > > article "5 kHz Bandwidth Restriction suits AM" by
> > George
> > >
> > > > W.
> > > > > Woodard, PE, Dec. 7, 2005 Radio World.
> > > > > This article not posted to web-No link yet
> available.
> > > > > The conclusions he reached are not supported by his
> > own
> > > > > data, and is contrary to the bulk of over 100 years
> of
> >
> > > > > acoustic, medical, and electronic research.
> > > > > His data and text show a -16 dB loss on his "Best"
> > > tested
> > > > > radio. At about 9000 Hz (NRSC-1 and 2 dictate high
> > > > frequency
> > > > > pre-emphasis and a 10, 000 Hz cutoff) for broadcast
> > AM.
> > > > When
> > > > > the preemphasis that he mentions is included, this
> is
> > > > > reduced to about -6dB. NOT BAD! I'll settle for
> that.
> > > > > Then he proposes that broadcast AM would sound
> better
> > > and
> > > > > more intelligible if the fidelity were cut in half
> to
> > 5
> > > > kHz
> > > > > with a "brick wall" filter. Perhaps on short wave
> > > > > communication where sky wave with selective fading
> and
> >
> > > > > selective sideband cancellation occur this might be
> an
> >
> > > > > advantage. In AM broadcast where the primary
> coverage
> > is
> > >
> > > > > ground wave, such effects are minimal.
> > > > > Almost all acoustic, medical, electronic, speech,
> and
> > > > other
> > > > > research strongly show higher fidelity, greater
> signal
> >
> > > to
> > > > > noise, lower distortion, improve natural sound and
> > > > > intelligibility. The research for this is
> compellingly
> >
> > > > > conclusive. If you have any doubt, study the
> research
> > or
> > >
> > > > ask
> > > > > any competent audiologist, medical doctor, acoustic
> > > > > engineer, or other professional.
> > > > > The link below is to a recent white paper showing
> that
> >
> > > > > speech intelligibility is increased with better
> > response
> > >
> > > > up
> > > > > to 14 kHz and there is a very significant loss of
> > > > > intelligibility when frequencies between 5 and 9 kHz
>
> > are
> > >
> > > > > missing. (See Figure 2).
> > > > http://www.po>
> > > >
> > >
> >
> lycom.com/common/pw_cmp_updateDocKeywords/0,1687,1809,00.pdf
>
> >
> > >
> > > >
> > > > >
> > > > > Add to this the very loud hiss created by HD
> > > > > radio-IBOC-iBiquity and AM radio is destroying
> itself.
> >
> > > The
> > > >
> > > > > level of the IBOC hiss belies it's actual loudness
> and
> >
> > > > loss
> > > > > of intelligibility because of the nature of the
> > digital
> > > > > waveform vs. analog waveform. Square waves are much
> > > louder
> > > >
> > > > > then sine waves of the same level. In addition, with
>
> > > most
> > > > > common radio detectors it is almost impossible to
> > > > completely
> > > > > tune out this annoying and distracting digital hiss.
>
> > > > > FM IBOC takes about 5 channels and is jamming
> favorite
> >
> > > > > nearby stations in populated metropolitan areas,
> where
> >
> > > > most
> > > > > listeners live. It does not take a genius to divide
> by
> > 5
> > >
> > > > the
> > > > > 100 available FM channels to see that about 20
> > unjammed
> > > > > channels is about the most you can expect in
> congested
> >
> > > > > metropolitan areas. (4 of those channels are likely
> to
> >
> > > > fall
> > > > > in the non-commercial low end of the dial leaving
> only
> >
> > > > about
> > > > > 16 commercial FM stations).
> > > > > The most favorable projections only predict that
> > perhaps
> > >
> > > > 10%
> > > > > of listeners will purchase HD radios in the next 5
> > > years.
> > > > > Can broadcasting as we know it survive with less
> then
> > > 10%
> > > > of
> > > > > it's current listeners?
> > > > > HD radio is an expensive, destuctive hoax.
> > > > > Sincerely,
> > > > > Richard Franklin
> > > > > HD RADIO=DIGITAL DISASTER!
> > > > > http://worldsupercaster.blogspot.com
> > > > >
> > > > Ma Bell did extensive research on frequency response
> and
> >
> > > > it's relationship to intelligibility. Mama says, and
> she
> >
> > > is
> > > > very smart, that 300-3000 Hz response is the bare
> > minimum
> > > > for speech. Additional bandwith is just not needed for
>
> > > > "intelligibility."
> > > > Now....does 10 khz (or 15 Khz) SOUND better? Why, of
> > > course!
> > > > But can the average AM radio reproduce anything above
> 3
> > > Khz?
> > > > No! Why waste transmitter energy on spectrum which
> > can't
> > > be
> > > > heard by 99.99% of the listeners?
> > > > I agree with the folks who think IBOC is not a mature
> > > > technology. It seems that the AM "hybrid mode"
> > technology
> > > is
> > > > hopelessly flawed for night service. It is time for
> > other
> > > > "different" ideas.....but AM stereo is not the answer.
>
> > > > I hear Leonard Kahn is perfecting a digital sparkgap
> AM
> > > > transmission system....wonder if you will have to have
>
> > two
> > >
> > > > radios to decode it?
> > > >
> > >
> >
>
 
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