On Aug 26, 10:30 pm, Bart Bailey wrote:

Maybe if you narrowed your bandwidth or used synchronous detection on
the far sideband you could do likewise? What kind of receiver are you
using? Does it have synchronous detection or pass band shift?

I'm talking about normal radios. I don't own any "communications
grade" gear (unless you want to count my Zenith Royal D7000Y, which I
don't).

I've owned ghetto blasters (yes! ghetto blasters) with very good
quality tuners that allowed me to pick up -- and comfortably listen to
-- stations like WICC AM 6 in Bridgeport, Conn., WMTR AM 1250 in
Morristown, NJ, and yes, even what was then WBLI-1240 (now WGBB) out
of Freeport, NY.

On a few run-of-the-mill 5-tube radios and pocket radios I would
sometimes be able to scrape out AM 1210 from Philadelphia. All during
the day.

Can't do this anymore. But that's unimportant Let's get on to a
topic that's more important for "joe random" AM listeners: The sound
quality of the analog signal.

I have a Kloss Tivoli table radio which is definitely not sensitive
on AM, but was designed to have have very decent sound for its little
size.

It's gotten to the point where it's gotten impossible to listen to an
IBOC AM station on one of these during the day because you ALWAYS hear
that "hisss" in the background. And please, find an excuse for the
"clipping" of the audio?

Fine, so I won't be able to DX. I can live with that, considering
it's not worth doing so anymore.
But can't I have at least the local stations sounding decent and
"clean" without something that sounds worse than over-driven cheap
magnetic tape hiss constantly buzzing in my ears?

Stephanie Weil
New York City, USA

On Aug 27, 12:38 pm, Bart Bailey wrote:

Orban's Opti-Mod I think it's called, and station personnel that can't
seem to resist adjusting them for maximum smoke.

Processors were always set "hot" way before IBOC came on the scene,
and I never heard station audio clip and distort the way it does now
on the analog side of AM HD. Reducing the available bandwith for
analog to +/- 5 khz to shoehorn the digital portion sure hasn't helped
either.

The whole idea with HD is that you have to back off on the processing
a bit. You can't overdrive digital the way you can with analog and
have it come out sounding good. It's like slightly overdriving a
recording on cassette tape vs. Minidisc. If you try it with Minidisc,
you hit a brick wall and everything above that starts sounding like so
much mush.

Stephanie Weil
New York City, USA

Stephanie Weil wrote:
On Aug 27, 12:38 pm, Bart Bailey wrote:

Orban's Opti-Mod I think it's called, and station personnel that can't
seem to resist adjusting them for maximum smoke.

Processors were always set "hot" way before IBOC came on the scene,
and I never heard station audio clip and distort the way it does now
on the analog side of AM HD. Reducing the available bandwith for
analog to +/- 5 khz to shoehorn the digital portion sure hasn't helped
either.

The whole idea with HD is that you have to back off on the processing
a bit. You can't overdrive digital the way you can with analog and
have it come out sounding good. It's like slightly overdriving a
recording on cassette tape vs. Minidisc. If you try it with Minidisc,
you hit a brick wall and everything above that starts sounding like so
much mush.

Stephanie Weil
New York City, USA



Clipping has been part of audio processing since the early days of
audio processing. It's usually inaudible. AM processing has been using
'smart' clipping for awhile, now. Smart clipping is not quite as
hard--rounded edges--but for a number of years CRL openly hard clipped
the composite baseband and let the **** fall into the filter where it may.

And not all analog clipping is that objectionable. It adds even order
harmonics, which are pleasing to the ear. If over done...well, that's
another story...but lightly, it can be a good thing...

One of the problems we have with digital audio, is the number of
analog engineers applyin analog thinking to digital audio. And this
applies to both recording and live audio, as well. You're right, digital
audio is a brick wall at '0', and anything beyond that becomes some
serious trash. Analog engineers, especially in the recording industry,
routinely try to recreate 'tape compression' at the top end, by driving
preamps and other pre conversion electronics mildly to their top end.
Especially if they're using tube preamps. This takes a delicate hand.
But who's that delicate is broadcasting, today? Not many.

The most common complaint I hear about HD reception, today, and this
applies to both AM and FM, is the audio quality isn't what is expected.
It's not CD quality, which according to Philips and Sony was only
supposed to be medium-fi in the first place. And the HD audio is nearly
always loaded with some kind of distortion artifact resulting from
trying to pack 5 lbs in a 4 lb bag.

Truth is, the very reasons we developed audio processing in the first
place still apply to the digital audio--limited headroom and the attempt
to control clipping distortions while retaining compelling listening.
Simply going digital is not changing those needs. While digital usually
has deeper dynamic range, on the soft end, there is still a finite,
limited ceiling at the max end, and that's where the most objectionable
distortion is. So, the same needs for processing still apply. Albeit in
different areas, with different parameters.

To provide compelling listening in the digital stream, engineers MUST
provide the proper dynamics and spectral controls.

But that costs money. And most HD streams are not self supporting.
And with Radio facing performance royalty payments, that's not likely to
change any too soon. Another reason why the HD battle is upstream.

The hard truth is that Radio in the main, isn't playing HD the way it
needs to be played to maximize it as a resource. Some are. There are
some very good sounding HD streams. But most aren't.

And they aren't likely to start. It's too much work, for too little
revenue return on the investment.

In article
,
D Peter Maus wrote:

Stephanie Weil wrote:
On Aug 27, 12:38 pm, Bart Bailey wrote:

Orban's Opti-Mod I think it's called, and station personnel that can't
seem to resist adjusting them for maximum smoke.

Processors were always set "hot" way before IBOC came on the scene,
and I never heard station audio clip and distort the way it does now
on the analog side of AM HD. Reducing the available bandwith for
analog to +/- 5 khz to shoehorn the digital portion sure hasn't helped
either.

The whole idea with HD is that you have to back off on the processing
a bit. You can't overdrive digital the way you can with analog and
have it come out sounding good. It's like slightly overdriving a
recording on cassette tape vs. Minidisc. If you try it with Minidisc,
you hit a brick wall and everything above that starts sounding like so
much mush.

Stephanie Weil
New York City, USA



Clipping has been part of audio processing since the early days of
audio processing. It's usually inaudible. AM processing has been using
'smart' clipping for awhile, now. Smart clipping is not quite as
hard--rounded edges--but for a number of years CRL openly hard clipped
the composite baseband and let the **** fall into the filter where it may.

And not all analog clipping is that objectionable. It adds even order
harmonics, which are pleasing to the ear. If over done...well, that's
another story...but lightly, it can be a good thing...

One of the problems we have with digital audio, is the number of
analog engineers applyin analog thinking to digital audio. And this
applies to both recording and live audio, as well. You're right, digital
audio is a brick wall at '0', and anything beyond that becomes some
serious trash. Analog engineers, especially in the recording industry,
routinely try to recreate 'tape compression' at the top end, by driving
preamps and other pre conversion electronics mildly to their top end.
Especially if they're using tube preamps. This takes a delicate hand.
But who's that delicate is broadcasting, today? Not many.

The most common complaint I hear about HD reception, today, and this
applies to both AM and FM, is the audio quality isn't what is expected.
It's not CD quality, which according to Philips and Sony was only
supposed to be medium-fi in the first place. And the HD audio is nearly
always loaded with some kind of distortion artifact resulting from
trying to pack 5 lbs in a 4 lb bag.

Snip

The bit rate is not high enough for high quality sound.

--
Telamon
Ventura, California