WJR hits the fan with iBiquity??

[davideduardo]

5KHz of audio isn't what I'd call having it "figured out" or 95 percent. Quite frankly it sucks. I'm sure the great back-east major market we-know-more-than-you-because-we're-from-NYC-engineering minds have done the best they can at optimizing poor audio quality, but only so much can be forced though something that's restricted. Supprisingly even the great minds of NYC engineering can't change the laws of physics. (we all feel so inferior out here in the "sticks" because we just can't figure it out with our 3rd grade one-room school edjumacation Shower us with your enlightenment oh great major market radio.. puke. ) AM IBOC is a poor trade of fidelity for future "benifits". 20 years from now it might be an acceptable practice. Right now it's only for practice, and there's no way in HELL it'll ever be perfect...

The NRSC comittee showed that the average consumer radio is off 10 db at 4.1 kHz, so rolling above 5 kHz has essentially no effect on the audio quality of AM as the receivers are the problem, not the transmission facility.

Go to http://www.nrscstandards.org/ and click "AM Bandwidth Study."

Reality is such a tough thing to accept.

 

[calstymes]

LinoNYC envisaged:

Yet more methane, boy, light a match near you and your toupee will blow-off.

I am quite fortunate that I do not yet need a toupee with my advancing age. Perhaps if I keep producing enough methane though, I will soon need one!

I don't know where in hell's-half-acre you reside, here in market #1 the AM's have this iboc thing figured out.

I reside in market #1, which is no secret. And you really think that the AMs in NYC have this IBOC thing figured out, eh? Well maybe at your station they do. If so, you have my sincerest congratulations.

I've posted recent analog airchecks of iboc running stations: WFAN,WOR, WABC, WNYC-am, and WCBS-am. All have their sound atleast 95% of what the pre iboc quality was.

Well if you say so. Obviously you are smarter than I am and I will therefore accept what you say.

Might I suggest that some of the enigineers in your neck-of-the-woods give a call to the CE's of the aforementioned stations.

I'll have them do that. What a wonderful and most useful suggestion.

I'am sure they'll be delighted to help.

No doubt and without question. Surely they are a helpful lot and will no doubt assist in confirming your position on this issue.

 

[Play Freebird]

The NRSC comittee showed that the average consumer radio is off 10 db at 4.1 kHz, so rolling above 5 kHz has essentially no effect on the audio quality of AM as the receivers are the problem, not the transmission facility.

Go to http://www.nrscstandards.org/ and click "AM Bandwidth Study."

Reality is such a tough thing to accept.

A couple of observations:

1) The study shows about 16 percent of the receivers (those beyond +1 standard deviation) had response at least 9 dB above average at 5 kHz. It's reasonable to assume that those are the higher quality receivers (such as factory-installed car radios) which account for significantly more TSL than than the cheap narrowband junk.

Please consider this: Wouldn't most of you consider your intelligence to be at least one standard deviation above average? How do you react to media content which is "dumbed down" to satisfy an audience or readership of average IQ or lower? Isn't it a pleasure to find programming or articles with content better than average?


2) The NRSC study concludes with the statement "...these data suggest that in general, consumers preferred lower bandwidths (between 5 and 7 kHz) to higher bandwidths." If this is indeed true (I have my doubts), what's the point of AM HD? It doesn't solve lightning or powerline noise problems (or the nighttime incoming skywave interference problem) because the digital component won't decode under those conditions; when the going gets tough, it craps out. So why are we spending all this money and trashing the band for a "benefit" that NRSC has concluded is unwanted?

 

[davideduardo]

1) The study shows about 16 percent of the receivers (those beyond +1 standard deviation) had response at least 9 dB above average at 5 kHz. It's reasonable to assume that those are the higher quality receivers (such as factory-installed car radios) which account for significantly more TSL than than the cheap narrowband junk.

Actually, only about 30% of radio listening is done in the car, so most listening and TSL come from those pesky narroband receivers.

Please consider this: Wouldn't most of you consider your intelligence to be at least one standard deviation above average? How do you react to media content which is "dumbed down" to satisfy an audience or readership of average IQ or lower? Isn't it a pleasure to find programming or articles with content better than average?

The fact that many sations have been able to do 6 kHz or even 7 kHz with HD shows that those few receivers that pass anything about 5 kHz can be satisfied. The fact is that most high quality receivers, such as component stereos, are not used for AM radio listening.

2) The NRSC study concludes with the statement "...these data suggest that in general, consumers preferred lower bandwidths (between 5 and 7 kHz) to higher bandwidths." If this is indeed true (I have my doubts), what's the point of AM HD? It doesn't solve lightning or powerline noise problems (or the nighttime incoming skywave interference problem) because the digital component won't decode under those conditions; when the going gets tough, it craps out. So why are we spending all this money and trashing the band for a "benefit" that NRSC has concluded is unwanted?

It's a whole different thing with fully broadband digital. AM is dying due to its terrible quality... 5 kHz or 7 kHz are both horrible, and explain why two generations of Americans don't listen to AM, and those who do are predominantly over 55. HD may not be the solution, but the alternative is the total probability of the death of AM... where the only viable format is moving faster and faster to FM.

 

[Dighton Rockhead]

From David Eduardo:

AM is dying due to its terrible quality... 5 kHz or 7 kHz are both horrible, and explain why two generations of Americans don't listen to AM, and those who do are predominantly over 55. HD may not be the solution, but the alternative is the total probability of the death of AM... where the only viable format is moving faster and faster to FM.

It's pretty safe to say that the last time AM radio sounded good to the majority of Americans was in the 30's & 40's, before the common availability of FM, and the only sound comparison they could make was to shortwave.

In those times, a vacumn-tube floor model radio with a 12 inch mono speaker was fully capable of producing a warm, rich, pleasing sound, especially with the somewhat wider band broadcasting that took place then.

It is kind of romantic to think of that era......the housewife doing her ironing while listening on that radio to NBC Red's "The Guiding Light", or "Ma Perkins" on CBS., or the family gathering that evening to listen to "Fibber McGee & Molly".

Too bad the times have changed a whole lot faster than AM radio's ability to keep up.

To me, AM HD's not the answer and my hope is it'll be leap-frogged, and replaced by something that works a whole lot better.

 

[Radioman100]

A couple of observations:

1) The study shows about 16 percent of the receivers (those beyond +1 standard deviation) had response at least 9 dB above average at 5 kHz. It's reasonable to assume that those are the higher quality receivers (such as factory-installed car radios) which account for significantly more TSL than than the cheap narrowband junk.

Please consider this: Wouldn't most of you consider your intelligence to be at least one standard deviation above average? How do you react to media content which is "dumbed down" to satisfy an audience or readership of average IQ or lower? Isn't it a pleasure to find programming or articles with content better than average?


2) The NRSC study concludes with the statement "...these data suggest that in general, consumers preferred lower bandwidths (between 5 and 7 kHz) to higher bandwidths." If this is indeed true (I have my doubts), what's the point of AM HD? It doesn't solve lightning or powerline noise problems (or the nighttime incoming skywave interference problem) because the digital component won't decode under those conditions; when the going gets tough, it craps out. So why are we spending all this money and trashing the band for a "benefit" that NRSC has concluded is unwanted?

So far this week I've been in a late model Chevy, a Ford and a Toyota which were all equipped with factory stereos. I listened to AM talk in all of them and I'm almost certain that none of them produced anything above 4k.

 

[Chuck]

So far this week I've been in a late model Chevy, a Ford and a Toyota which were all equipped with factory stereos. I listened to AM talk in all of them and I'm almost certain that none of them produced anything above 4k.

Probably so, but was anything with content over 4-5 KHz actually transmitted to those radios? Probably not. It is pretty hard to hear something that isn't there in the first place.

 

[Radioman100]

So far this week I've been in a late model Chevy, a Ford and a Toyota which were all equipped with factory stereos. I listened to AM talk in all of them and I'm almost certain that none of them produced anything above 4k.

Probably so, but was anything with content over 4-5 KHz actually transmitted to those radios? Probably not. It is pretty hard to hear something that isn't there in the first place.

I'm sure it was. I tuned around and didn't hear anything above 4k, even on the Spanish music stations.

 

[LinoNYC]

OK, I just dropped this onto my automation system, and I have other mint Batman audio to compare with, so I'll be back later to report.

Every time I see Lino, I HAVE to think linotype or linoleum, and I know that's not what you want associated to lino, whazzat mean?


I suspect that like in chicago, they've got sibilance back, or a far more useful version of sibilance than er, previously to the upgrade "that didn't happen".

These message boards often atract a certain type of "wannabe" who while desparate to show their "knowledge" about the topic at-hand end up showing their ignorance of everything else.

Lino is a common Spanish name, pronounced lee-no. While I'am blond and about as Anglo as can be, I was born in Mexico City in 1956.

I am Mexican.

" I just dropped this onto my automation system, and I have other mint Batman audio to compare with, so I'll be back later to report.

"Automation system"-Pentium 2, Win98 Radio Shack speakers

Lino

 

[Chuck]

I'm sure it was. I tuned around and didn't hear anything above 4k, even on the Spanish music stations.

I can't speak for your car radio experiences, but in my area there is a 5 KW day-timer playing music that actually has some "near highs" and pleasant low end. Imagine that, bass. Bass is your friend. It covers up a lot of perceived problems. This particular station is not rolled off at 5 KHZ and it is VERY easy to tell that it has vastly superior audio than many AMs when I listen in my 2007 Chevy Tahoe factory Bose radio.

Not that long ago, I rented a Chrysler car, and was amazed at the top end on AM (assuming the station had any). It did not sound as good as FM but it was very pleasant sounding on music and quite easy to get used to.

The fact of the matter is many radios do have response over 4-5 KHZ, NRSC study not withstanding. People who buy $12.99 clock radios at Walgreen’s are treated with equally crapppy sound on either AM or FM. Have you ever listen to the Sunbeam radio that you will find in many hotel rooms? It's almost impossible to figure out if it is on AM or FM. Both sound equally horrid. HD will not cure that problem.

 

[mimo]

truthfully, there are few, if any, clock radios that are any better than glorified pocket radios. They sound about the same and many have even worse sensitivity. The only difference is they have a clock and plug into a wall.

 

[davideduardo]

Lino is a common Spanish name, pronounced lee-no. While I'am blond and about as Anglo as can be,

One of my high school classmates, Carlos Mantilla, was so "rubio" we called him "Gringo" or "El gringo Mantilla"

I was born in Mexico City in 1956.

When you were 7, I was interning with Ramiro Garza and Francisco Aguirre, Jr., at Radio Centro at Artículo 123 #90.

 

[Tom Wells]

OK, I just dropped this onto my automation system, and I have other mint Batman audio to compare with, so I'll be back later to report.

Every time I see Lino, I HAVE to think linotype or linoleum, and I know that's not what you want associated to lino, whazzat mean?


I suspect that like in chicago, they've got sibilance back, or a far more useful version of sibilance than er, previously to the upgrade "that didn't happen".

These message boards often atract a certain type of "wannabe" who while desparate to show their "knowledge" about the topic at-hand end up showing their ignorance of everything else.

Lino is a common Spanish name, pronounced lee-no. While I'am blond and about as Anglo as can be, I was born in Mexico City in 1956.

I am Mexican.

" I just dropped this onto my automation system, and I have other mint Batman audio to compare with, so I'll be back later to report.

"Automation system"-Pentium 2, Win98 Radio Shack speakers

Lino

Wow, Lino, calm yourself. You must learn to take me at face value. I really do wear my heart on sleeve an do not snipe.
I honestly wished to clear away the associations I mentioned. I have worked in Mexico City 3-4 times and San Juan del Rio a few times, known Franciscos,
Evaristos, and Humbertos, but no Linos. I have no preconscrewed notions about any group, and my neighborhood has 91 languages.

I reported in early september on the " return of sibilance" to Chicago 50kw AM iBOCs.

We were running out the door to visit family and instead of saving the file to the desktop, I saved into a Zara automation directory, and
put it into the list right after a Nancy Sinatra from 1966 , but before a 1966 Batman-themed Plymouth spot and "Batman Chase" by Neil Hefti.
The "mint" Batman audio is not yet online, so I'll be comparing from memory.
I think the computer is a Celeron 786mhz w/W2000 that was undersized for a customer's need even at time of install.
It aged unused for 2 years, and I took it home and have begun loading it up with my own demented format, thank you.
Someday soon I will record one random hour and post a file-share recorded from a good AM receiver.
I have lost track of how many issued laptops I have been through over the years. I never buy computers.

I am a glad-I-knew-enough-to-stay-out, rather than a wanna-be.

I did listen to the file on 2 radios as broadcast by Zara over pt 15 AM 1620 30-20,000 hz, and the servers' own speakers.
I was pleased with the crisp sibilance, so much that the listening over the server speakers ( not via AM radio) made me almost believe this was from
a studio monitor. It is that crisp. But I haven't yet checked the file bitrate. I DID hear in each radio and computer spkrs the lower-and-better sort of hiss
rather than the old transmitter-blower type of air-leak hiss. As of now, I haven't yet listened on headphones, but I will report back and tell you
just how bad the hiss was. As I reported in the early Sept post, this upgraded version borders on tolerable for local listening, if kept low.
If anything it sounds by what I heard on radios and speakers earlier this AM, that WABC sounds even better than WLS. Maybe it's just that radio.
Fine recording, by the way. It seems to be full quieting. How many miles out was this?
For sure, this sounds way better than any of the files posted by RF Burns.


Mr Eduardo, Are you maintaining that no revised spectral-distribution/upper-end/sibilance-enhancements have been implemented?
My ears have never lied to me yet.

I do not disrespect those in the business. With my engineering background and experience, I do say what I say from my
best considered reasoning, even when I am sometimes severe in my tone.

 

[RadioFixerCLE]

Lino is a common Spanish name, pronounced lee-no. While I'am blond and about as Anglo as can be, I was born in Mexico City in 1956.

From my childhood (back in 1988) I remember a talk show host on WADO 1280 who was named Lino Cruz. He used to do a PM drive show with Gisela García (who is still at WADO, by the way).

For a second there, I thought that was you, but I don't think he was Mexican. He was either Cuban or Puerto Rican, I can't remember.

 

[Tom Wells]

The best recording posted so far- tell more.
The hiss is still there and/but is improved on pt 15 listening hifi by liberal application of variable high-end filtering, as
all previous and all HD hybrid analog samples. My wife could immediately hear when I stripped out the hiss.
It's beautiful with the hiss stripped, and it now will be on my part 15 with WABC props.

 

[Kelly]

This, (along with the old AM Stereo bbs), has dealt with the AM receiver audio response issue numerous times. But, because it's been a few years since I ran my own updated test, albeit somewhat quick, I thought it would be time to revisit the subject with my stable of vehicles. Now rather than taking a feed directly off the AC output to the speakers, assuming impedance matching issues, speaker audio reponse, etc., I decided to measure response using a White Instruments audio spectrum analyzer, and a microphone with a known response curve, (Electrovoice RE-20 set to flat EQ), right out of the various vehicle speakers. Below is the result. The two vehicles sampled were my 1998 Jeep Cherokee with a Chrysler factory AM-FM-CD-Cassette unit, equalizer set at flat. Measurements were taken at the door speakers, microphone on a stand one foot away. Audio was sampled from four different FM, four different AM stations, and one AM station currently running AM-HD. BTW, the Jeep radio has a AM Stereo tuner, but there are no stations currently running AM stereo in the market. The same test was run on my 2006 Lexus GS with a Mark Levinson sound system. Of particular note was the high frequency response. Because there was no AM music stations, where possible samples were made from similar, or the same commercials running on both AM and FM stations which contained music and voice in combination. The analyzer was set for a 3 minute peak and hold sample for each station, stored and reviewed when the testing was completed.

Lexus 3 minute unweighted Station 1, (News Talk) Low Frequency cut-off -10db at 250hz. High Frequency cut off was -10db at 2.8kHz, (voice and commercial music).

Exact same response for similar stations 2, 3, 4, and the AM HD station, (Radio Disney format). Based on the results, one could assume that response limitations were related to the AM tuner.

Lexus 3 minute unweighted FM station 1, (Classic Hits), Low Frequency cut off -10db at 65hz. High Frequency cut-off was -10 at 12.3kHz, (voice and commercial music).

Lexus FM Station 2 was CHR, LF -10db 52Hz, HF -10 at 12.3KHz.

Lexus FM Station 3 was Classical, LF -10db 64hz, HF -10 at 12.3kHz.

Lexus FM Station 4 was AAA, LF -10db 58hz, HF -10 at 12.3kHz.

Jeep 3 minute unweighted Station 1, (News Talk) Low Frequency cut-off -10db at 140hz. High Frequency cut off was -10db at 3.5kHz, (voice and commercial music).

Jeep AM Station 2, and 3 were the same response.

Jeep AM Station 4 was less frequency response both LF and HF, LF cut off -10 at 200hz, HF cut off was -10db at 2.8kHz.

Jeep AM-HD Station, (Radio Disney), LF -10 at 250hz, HF cut off -10 at 2.8kHz. I heard no data noise in the analog audio.

Jeep 3 minute unweighted FM station 1, (Classic Hits), Low Frequency cut off -10db at 80hz. High Frequency cut-off was -10 at 11.8kHz, (voice and commercial music).

Jeep FM Station 2 was CHR, LF -10db 52Hz, HF -10 at 10.5KHz.

Jeep FM Station 3 was Classical, LF -10db 65hz, HF -10 at 12.3kHz.

Jeep FM Station 4 was AAA, LF -10db 60hz, HF -10 at 12.5kHz.

 

[Tom Wells]

This, (along with the old AM Stereo bbs), has dealt with the AM receiver audio response issue numerous times. But, because it's been a few years since I ran my own updated test, albeit somewhat quick, I thought it would be time to revisit the subject with my stable of vehicles. Now rather than taking a feed directly off the AC output to the speakers, assuming impedance matching issues, speaker audio reponse, etc., I decided to measure response using a White Instruments audio spectrum analyzer, and a microphone with a known response curve, (Electrovoice RE-20 set to flat EQ), right out of the various vehicle speakers. Below is the result. The two vehicles sampled were my 1998 Jeep Cherokee with a Chrysler factory AM-FM-CD-Cassette unit, equalizer set at flat. Measurements were taken at the door speakers, microphone on a stand one foot away. Audio was sampled from four different FM, four different AM stations, and one AM station currently running AM-HD. BTW, the Jeep radio has a AM Stereo tuner, but there are no stations currently running AM stereo in the market. The same test was run on my 2006 Lexus GS with a Mark Levinson sound system. Of particular note was the high frequency response. Because there was no AM music stations, where possible samples were made from similar, or the same commercials running on both AM and FM stations which contained music and voice in combination. The analyzer was set for a 3 minute peak and hold sample for each station, stored and reviewed when the testing was completed.

Lexus 3 minute unweighted Station 1, (News Talk) Low Frequency cut-off -10db at 250hz. High Frequency cut off was -10db at 2.8kHz, (voice and commercial music).

Exact same response for similar stations 2, 3, 4, and the AM HD station, (Radio Disney format). Based on the results, one could assume that response limitations were related to the AM tuner.

Lexus 3 minute unweighted FM station 1, (Classic Hits), Low Frequency cut off -10db at 65hz. High Frequency cut-off was -10 at 12.3kHz, (voice and commercial music).

Lexus FM Station 2 was CHR, LF -10db 52Hz, HF -10 at 12.3KHz.

Lexus FM Station 3 was Classical, LF -10db 64hz, HF -10 at 12.3kHz.

Lexus FM Station 4 was AAA, LF -10db 58hz, HF -10 at 12.3kHz.

Jeep 3 minute unweighted Station 1, (News Talk) Low Frequency cut-off -10db at 140hz. High Frequency cut off was -10db at 3.5kHz, (voice and commercial music).

Jeep AM Station 2, and 3 were the same response.

Jeep AM Station 4 was less frequency response both LF and HF, LF cut off -10 at 200hz, HF cut off was -10db at 2.8kHz.

Jeep AM-HD Station, (Radio Disney), LF -10 at 250hz, HF cut off -10 at 2.8kHz. I heard no data noise in the analog audio.

Jeep 3 minute unweighted FM station 1, (Classic Hits), Low Frequency cut off -10db at 80hz. High Frequency cut-off was -10 at 11.8kHz, (voice and commercial music).

Jeep FM Station 2 was CHR, LF -10db 52Hz, HF -10 at 10.5KHz.

Jeep FM Station 3 was Classical, LF -10db 65hz, HF -10 at 12.3kHz.

Jeep FM Station 4 was AAA, LF -10db 60hz, HF -10 at 12.5kHz.

The AM high frequency response of these radios is poor enough to consider them useless.
Why would anyone keep such a radio for more than the time it took to get a real replacement?
If you'd like me to send you an old slug-tuned AM car radio, I could modify it for the expanded band and sell it
for next to nothing. You'd see what what a properly engineered AM radio can sound like.

I really do have several extras if you're interested.

It is lamentable such garbage exists. There may be ways to widen the AM response up on those radios.
The only real way to hear AM correctly is with a continously tuned receiver.
Only in this way can one select an IF passband "slice" which will reproduce the audio without frequency distortion.
ALL center tuned-only radios create frequency distortion whenever they do not pass the full audio modulation of the original signal.
This frequency distortion is desirable in SW communications, but not in Broadcast.
Unless everybody is using these car radios to dx AM at night, they're designed wrong.

 

[Radioman100]

Thanks Kelly for taking the time! Very informative.

 

[Kelly]

[/quote]

The AM high frequency response of these radios is poor enough to consider them useless.
Why would anyone keep such a radio for more than the time it took to get a real replacement?
If you'd like me to send you an old slug-tuned AM car radio, I could modify it for the expanded band and sell it
for next to nothing. You'd see what what a properly engineered AM radio can sound like.

I really do have several extras if you're interested.

It is lamentable such garbage exists. There may be ways to widen the AM response up on those radios.
The only real way to hear AM correctly is with a continously tuned receiver.
Only in this way can one select an IF passband "slice" which will reproduce the audio without frequency distortion.
ALL center tuned-only radios create frequency distortion whenever they do not pass the full audio modulation of the original signal.
This frequency distortion is desirable in SW communications, but not in Broadcast.
Unless everybody is using these car radios to dx AM at night, they're designed wrong.


[/quote]

Actually my Mark Levinson FM section in the Lexus sounds very good, and is true diversity, with an antenna front and rear, so multipath is pretty rare without the "blending" and HF roll-off that the Chrysler radio does during multipath conditions. The AM section is VERY sensitive, but at the cost of frequency response. What was surprising was the Jeep Chrysler radio had not much better performance with the AM stereo capabilities built in. And because of the different stations, formats, etc., it appears the station audio performance had little to do with the receiver response. In the Lexus, the radio is built into my touch screen navigation system/climate controls, CD-DVD etc. Aftermarket radios are out of the question in a car like this. Besides, all the advantages, and performance of the system easily outweigh the poor AM frequency response.

 

[JohnnyElectron]

Speaking of great-sounding AM stations, I've noticed (on a 1995 vintage wide-band AM stereo radio) that AM 1000 from Chicago puts out some really nice 10KHz audio. Anyone noticed this? (that's in addition to the wide-bandwidth great-sounding music from AM[st] 630 CFCO from SW Ontario)