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Old August 14th 03, 03:20 PM
WBRW
 
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Default Can Digital AM ever sound this good?

Take a listen to the AM Stereo airchecks on this site:

http://www.1240keva.com/airchecks/

KEVA is an 880-watt Class C station in Evanston, Wyoming, using a
vintage McMartin vacuum tube (valve) transmitter and a complete
1983-era audio chain: a CRL AM Stereo Preparation Processor, a CRL AM
Stereo Maxtrix Processor, and a Motorola C-Quam AM Stereo Exciter.

The audio in the MP3 clips was recorded from KEVA's Motorola AM Stereo
Modulation Monitor, so you are hearing KEVA exactly as they sound on
the air -- not from a direct feed from their audio board.

Now, for those of you who have heard IBOC or DRM... can digital AM
ever sound this good? I don't think so... there's only so much
quality you can squeeze out of a 20 to 36 kbps data stream. At this
point, neither IBOC nor DRM have managed to eliminate the swishy,
gritty, phasey, heavily artifacted "28.8K RealAudio Web-Cast" type of
sound from their digital audio. And except for a MAJOR revolution in
the science of "lossy" audio compression, I don't think they ever
will.

Digital does have its advantages... but not in AM audio quality!


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Old August 14th 03, 06:07 PM
Dexter J
 
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Salutations:

WBRW wrote:

Take a listen to the AM Stereo airchecks on this site:

http://www.1240keva.com/airchecks/

KEVA is an 880-watt Class C station in Evanston, Wyoming, using a
vintage McMartin vacuum tube (valve) transmitter and a complete
1983-era audio chain: a CRL AM Stereo Preparation Processor, a CRL AM
Stereo Maxtrix Processor, and a Motorola C-Quam AM Stereo Exciter.

The audio in the MP3 clips was recorded from KEVA's Motorola AM Stereo
Modulation Monitor, so you are hearing KEVA exactly as they sound on
the air -- not from a direct feed from their audio board.

Now, for those of you who have heard IBOC or DRM... can digital AM
ever sound this good? I don't think so... there's only so much
quality you can squeeze out of a 20 to 36 kbps data stream. At this
point, neither IBOC nor DRM have managed to eliminate the swishy,
gritty, phasey, heavily artifacted "28.8K RealAudio Web-Cast" type of
sound from their digital audio. And except for a MAJOR revolution in
the science of "lossy" audio compression, I don't think they ever
will.

Digital does have its advantages... but not in AM audio quality!


I agree broadly with your conclusions regarding IBOC/DRM - however - you
are incorrect in labelling low kbps RealAudio as being completely awful..
It depends on the site specification regarding the codex and how carefully
the site administrator works on the sound objects/transaction model prior
to conversion..

I'm generating very close to AM stereo quality RealAudio at fixed 20kbs
without that 'bottom of the well' sound or any buffer problems on low speed
connections world-wide - have a poke around the site below.. I run 40-45
streams per 1mbs of outbound pipe and still feed a general site through the
same server head..

I have picked up a number of wireless/mobile users over the past year given
that my feed doesn't overload their available bandwidth at the CPU while
still providing a pretty sound quality at G2+ and I have been suggesting on
and off that WiFi may provide for a better over all software based receiver
model.. I can do the same with video feeds - but that limits the feeds to
about 20 streams per 1mbs or pipe and advanced Flash/SMIL falls somewhere
around 30 feeds per 1mbs outbound..

I apologize and say again that I'm not really a RealAudio zealot or
anything - I can't even get them to list my little bitcaster on their
site.. But credit where it is due - it's a pretty good codex and
multi-media streaming solution overall.. Broadly ported to *many* operating
systems and codex too..

I wonder now if the same model applies to IBOC/DRM.. Can you force minimum
kbps before accepting transmission as viable? If so - does it improve the
quality at the receiver head while limiting some of the problems you have
outlined?

A LOT of the complaints related to RealAudio have MUCH more to do with
bitcasters cheaping out, not really understanding the details at the
server/codex or trying to mess around client side for the marketing bulls
rather than anything particularly wrong with the particular multi-media
solution itself..

--

J Dexter - webmaster - http://www.dexterdyne.org/
all tunes - no cookies no subscription no weather no ads
no news no phone in - RealAudio 8+ Required - all the Time

Radio Free Dexterdyne Top Tune o'be-do-da-day
Sinatra Martin Davis - Ain't That A Kick in the Head
http://www.dexterdyne.org/888/036.RAM

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Old August 16th 03, 08:31 PM
Joe Blow
 
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Can Digital AM ever sound good?

Not as good as analog.

Analog cell phones sound better than digital cell phones.
Analog Laser Discs look better than digital DVDs.
Analog cable looks and sounds better than digital cable.

Why would digital AM sound better than analog AM?



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Old August 16th 03, 08:33 PM
CA was in NJ
 
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WBRW wrote:

The audio in the MP3 clips was recorded from KEVA's Motorola AM Stereo
Modulation Monitor, so you are hearing KEVA exactly as they sound on
the air -- not from a direct feed from their audio board.


plug If you're looking for the guy who made the recordings, he hangs out
at utahradionews.com /plug




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Old August 18th 03, 03:22 PM
Someone
 
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"Jake Brodsky" wrote in message ...

The beauty of digital broadcasting is that it works
better overall in a wider variety of conditions and the radio doesn't
have to be outrageously large, heavy, expensive, or high maintenance.


TRANSLATION: You will learn to like digital broadcasting because we
can provide it very cheaply, and we're looking for numbers, not quality.



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Old August 18th 03, 03:23 PM
Bob Haberkost
 
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But (and I can't believe this hasn't been argued before....but then I've been gone
for a while)....IBOC is the WRONG way to do this, on AM or FM.

Frankly, given the way the broadcast industry has handled audio processing and
programming, it really won't make a damn bit of difference whether it;s IBOC or in a
new service - it'll still sound like crap. I've said for a long time now that
current owners of any broadcast operation shouldn't be permitted to apply for, let
alone be granted, a new digital license. Of course, it may just be this concern that
U-S broadacasters have opted for IBOC in the first place, since they already "own"
the allocation. Less competition.

AM is dead, FM is dying, and they can have their IBOC in its dying days. In the end
the only broadcasting left will be the satellite-subscription services, and you'll
need to pay for that, just like everything else worth watching or listening to.
--
For direct replies, take out the contents between the hyphens. -Really!-



"Jake Brodsky" wrote in message
...
On 14 Aug 2003 14:20:24 GMT, (WBRW) wrote:

Digital does have its advantages... but not in AM audio quality!


Sigh. There are those who can show better performance using vinyl
records than a CD recording, and there are those who can show really
good performance with a tube amplifier.

--BUT THAT'S NOT THE POINT.

Unless you're really close to this broadcast station and your AM
receiver is of unquestionable quality, you'll never know the
difference. The beauty of digital broadcasting is that it works
better overall in a wider variety of conditions and the radio doesn't
have to be outrageously large, heavy, expensive, or high maintenance.

Don't misunderstand me, this station probably is quite an achievement.
Unfortunately its an achievement that will hardly get noticed but for
maybe a handful of listeners. That's the unfortunate fact of life.

The halls of technological progress are littered with high performance
efforts like these...


Jake Brodsky

"Never mind the Turing Test, what about the Turing Graduates?"



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Old August 18th 03, 03:23 PM
Tom Desmond
 
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Joe Blow wrote:

Analog cable looks and sounds better than digital cable.


And both look terrible compared to over-the-air DTV, which can far
exceed the quality of analog cable or analog broadcast.

As for digital cable -- as overcompressed as it typically is, it should
hardly be used as an example of what digital is capable of.

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Old August 19th 03, 03:21 PM
R J Carpenter
 
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"Jake Brodsky" wrote in message

...

The beauty of digital broadcasting is that it works
better overall in a wider variety of conditions and the radio doesn't
have to be outrageously large, heavy, expensive, or high maintenance.


Weird claims.

Digital broadcasting does not affect the size, weight, or maintenance of a
radio. It may increase the price. The digital signal is certainly is more
fragile than AM. Analog AM smoothly fades into the interference and noise -
digital quits.

In fact digital may increase the weight of a battery-powered radio because
of the current drain of the digital processing chips - at least in early
versions.

The size of a radio is determined largely by how good you want it to sound.




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Old August 19th 03, 03:21 PM
tony sayer
 
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Default

In article , Tom Desmond
writes
Joe Blow wrote:

Analog cable looks and sounds better than digital cable.


And both look terrible compared to over-the-air DTV, which can far
exceed the quality of analog cable or analog broadcast.


Well you must have some terrible analogue signals where you are if you
reckon that DTV is better!..

Our off air analogue from Sandy Heath out does DTV all the time and the
NICAM sound is better that the MPEG equivalent..


As for digital cable -- as overcompressed as it typically is, it should
hardly be used as an example of what digital is capable of.


--
Tony Sayer




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