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NYC HD Demo

autopaint-1 said:
Taking into acount that these recordings were made on a cassette recorder using a Sony TCM 5000 and of course the file has been reduced to 196 Kb from the wave original. You can hear for yourself approx. what HD sounds like at my QTH by downloading the file I have uploaded at the following address from my computer:

http://www.yousendit.com/transfer.php?action=download&ufid=40C53A455E3E658F
Click to expand...


I especially like the AM demo with the nice HET, then it goes away when HD kicks in.

I should put up some of my AM HD station (music) The first time I put it on the air I was stunned at how good it sounded. Audio processing is so critical for AM HD. Else you end up with digital artifacts.
 
"I should put up some of my AM HD station (music) The first time I put it on the air I was stunned at how good it sounded. Audio processing is so critical for AM HD"

I'd appreciate hearing your efforts. What are the call letters of your facility? By the way the noise on the WNYC signal was computer generated. The B.A. radio, a computer and a television are in the same room and all three were operating at the same time. What my demo also showed is how well the radio works, some 25 miles north of NYC with it's dipole antenna. This is for all the people who insist that reception problems are the result of technology as opposed to faulty receivers. It should be noted that I didn't include HD station which don't contain 2nd or 3rd channel audio on FM and those stations not broadcasting in English. (WWPR and WADO)
 
Thanks for taking the time to post the audio samples. Some examples sound better than others, but I suspect that all are "good enough" for most listeners. I've found, at least in the world of streaming audio, that most people are very happy with 48Kbs audio streams, and many are content with 32 KBs streams. Most people are quite satisfied with the audio they get from Sirius or XM as well, although I think both sound a little odd. It doesn't surprise me in the least that most people will find HD-2 channels to be quite adequate.

Have you ever notice what an amazing processing device the human brain is? A good example is going to a rock concert. Even with today’s technology, they usually start sounding quite awful, but as your brain gets used to the information your ears are delivering, things seem to get better. By the third song, you find yourself getting quite used to what is going on, and actually enjoying it. For the most part, it is your brain that is doing that. And all this time, you thought it just took a while for the soundman to get his act together. OK, sometimes that happens too, but for the most part, it is psychoacoustics. Your brain is compensating for the poor acoustics of the venue, or the tonal imbalance of the sound system. Because you can see the performers, your eyes help your brain pick up that guitar solo. The sound man doesn’t need to do a thing. The fact that you can process complex data and add the missing parts is why any compression codec works. HD radio is no different.

Even though most people will acknowledge that it sounds fine, I don't think audio quality is the "killer app" for HD radio. Most people are not audio purists. Have you ever listened to some peoples car stereos? You can't miss some of them as they drive by. By and large, they do not sound good. They certainly aren't accurate reproducers of music. Usually, they are simply loud with very over-exaggerated bass. Some people seem to actually like distortion. The sound of a boom box running at a clip due to low batteries and high volume is actually considered "good" by a large segment of the market. To be blunt, most people are tone deaf, or simply don't care about audio quality. This may come as a shock to those of us who value good audio, but our views are not shared by the majority of the listening public.

For HD to be a success, you'd better have something that people actually want to hear on these secondary (and even primary) channels. Sorry, content is king. Most people could care les about the technology involved. The system used also needs to get along well and play nice with its neighbors in the RF spectrum. It seems that that can usually be done in the FM band, although I know of one PubCaster in the Finger Lakes area of N.Y. that is having difficulty with interference issues caused by close spacing. They’ve had to shut off their HD feed, until they come up with a solution. Or at least, so says their Chief Engineer.

Whether this technology will "play nice" on the AM band, remains to be seen. That doesn't look as hopeful, unless the station decides to go "digital only." That isn't likely to happen for a long time.

In the mean time, it is an interesting spectator sport.
 
"Thanks for taking the time to post the audio samples. Some examples sound better than others, but I suspect that all are "good enough" for most listeners."

Thanks for taking the time to listen. A few points need to be made. First we're dealing with compressed audio and on the AM side we're talking about low bit rate compressed audio. There's not much left of the signal by the time it reaches the listener. Interference as you heard on the WNYC AM signal causes lots of error correction in the receiver and I took that audio, dubbed it to cassette tape (no noise reduction and standard grade 120 tape was used) and after transferring the audio to my hard drive I recompressed the audio at 192 KBS. That of course ads to the artifacts heard in the audio. While artifacts are audible on the AM transmissions, they generally are not from any of the FM broadcasters.


"I've found, at least in the world of streaming audio, that most people are very happy with 48Kbs audio streams, and many are content with 32 Kbps streams. Most people are quite satisfied with the audio they get from Sirius or XM as well, although I think both sound a little odd. It doesn't surprise me in the least that most people will find HD-2 channels to be quite adequate."

A lot has to do with the audio chain. It is a learning experience setting up an HD station. It's all new technology after all. Most people don't focus on sound or video as long as they can hear or watch the program. I am a DirecTV user and while I love their service I also can see the effects of their digital processing. The video is pixilated under certain conditions. Most people don't really care and it's the vast majority of people these companies are trying to serve.

"Have you ever notice what an amazing processing device the human brain is? A good example is going to a rock concert. Even with today’s technology, they usually start sounding quite awful, but as your brain gets used to the information your ears are delivering, things seem to get better. By the third song, you find yourself getting quite used to what is going on, and actually enjoying it."

How many years before the advent of FM radio was AM satisfactory for music with all its limitations, or how about those noisy 78 or vinyl albums/singles? Analogue tape hiss? We lived with it for many years. Such is the human minds filtering ability.

"Even though most people will acknowledge that it sounds fine, I don't think audio quality is the "killer app" for HD radio."

HD is a commercial slogan stolen from television. HD radio on FM really is no more high definition than current Analogue FM. What it does provide is the ability to program separate audio on at this time up to 3 different streams. That is something that analogue is unable to do without extending the broadcast band.


"Most people are not audio purists. Have you ever listened to some peoples car stereos? You can't miss some of them as they drive by. By and large, they do not sound good. They certainly aren't accurate reproducers of music."

Even with excellent systems the mobile environment is not the greatest for quality sound.


"For HD to be a success, you'd better have something that people actually want to hear on these secondary (and even primary) channels. Sorry, content is king."

Absolutely and at least here in NYC the HD2's run musical content unavailable elsewhere in the market and at least at this time there is a non compete agreement amongst broadcasters in NYC. We won't end up with ten more urban HD2 stations. That is a major plus.


"Whether this technology will "play nice" on the AM band, remains to be seen. That doesn't look as hopeful, unless the station decides to go "digital only." That isn't likely to happen for a long time."

And a major drawback at least at this time is the daylight only rule. It may be time to go back to having the old daytime stations sign off at sunset. It won't happen but that would be very helpful to cut down on interference.


In the mean time, it is an interesting spectator sport.
 
autopaint-1 said:
In the mean time, it is an interesting spectator sport.
Click to expand...

Well, we actually agree on your last post. I'm just happy that I don't need to invest in HD right now. I've always enjoyed new technology. At one time I considered myself an "early adopter," but for this one, being on the trailing edge is OK by me.

At the moment, the FMExtra system warms my water a lot more than IBOC. It’s simple, and it’s cheap. There is a lot to be said for that. Of course, there are absolutely no receivers available to receive it. At least "HD" has that going.

By the way, I'm interested in how the "non-compete" part of the Alliance works. It doesn't sound that far away from price fixing, or collusion, neither of which is legal. Any idea how they are getting around those issues? Maybe nobody is looking? Or is it simpler than that? Just curious.
 
I'd also like to thank you for posting that demo.

Not to be too much of an audiophile, but HD2 sounds like an Internet stream to me. It has that distinctive metalic sound in the treble.

Unlike an earlier post, I don't often consider 32k and 48k streams as listenable. There are SO many streams available at 96k and 128k (just browse around the iTunes Radio Tuner, for instance), why settle for less?
 
"Not to be too much of an audiophile, but HD2 sounds like an Internet stream to me. It has that distinctive metalic sound in the treble.

Unlike an earlier post, I don't often consider 32k and 48k streams as listenable. There are SO many streams available at 96k and 128k (just browse around the iTunes Radio Tuner, for instance), why settle for less?"

As I posted earlier, the sound on the radio is significantly better. The audio here has been copied to a poor quality feric casette and redigitized. In the end you are hearing audio which has been recompressed which of course will create further problems which might not exist in the original. I should make a DAT recording and maybe post them as wav files but that would take way too long to download. The advantage IBOC has over the internet is that it's not all that easy to drive around with a computer attached to internet at this time.
 
SmokeRing said:
Unlike an earlier post, I don't often consider 32k and 48k streams as listenable. There are SO many streams available at 96k and 128k (just browse around the iTunes Radio Tuner, for instance), why settle for less?
Click to expand...

I don't think I said they were "High Fidelity," but my experience says that a lot of people do find lower bit rate streams to be acceptable. We stream our station at 32KBs, which sounds better than I thought it would. I've experimented with increasing the streaming speed, but too many listeners complained about buffering problems, so I reluctantly went back to the 32KBs stream. It seems that not everybody has a great Internet connection.

Like IBOC, Internet streaming is an emerging technology. Sure it's been around a while, but it continues to develop. It wasn't that long ago when almost all streams sounded horrible.
 
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