It seems to me that the biggest difference in sound quality between a
released CD or DVD and an analog stereo TV or radio broadcast is the
sometimes severe DRC applied to the broadcast. I can understand it if the
form of transmission makes it necessary, but I don't understand why cable TV
channels do it. For example, the Ovation arts channel in Australia transmits
orchestral music with _extremely_ severe DRC. They also seem to artificially
increase the proportion of high frequencies during the "loud" parts, I
suppose to give the listener the illusion that it's really getting louder.
The DRC alone is bad enough, but in addition it's as though someone is
winding the treble knob up and down throughout. The result is truly ghastly.
These days people are paying a fortune for hi-fi home theatre systems, but
the channels continue to transmit pure crap. Why do they do it?

David

"David White" wrote in message
...
It seems to me that the biggest difference in sound quality between a
released CD or DVD and an analog stereo TV or radio broadcast is the
sometimes severe DRC applied to the broadcast. I can understand it if the
form of transmission makes it necessary, but I don't understand why cable
TV
channels do it. For example, the Ovation arts channel in Australia
transmits
orchestral music with _extremely_ severe DRC. They also seem to
artificially
increase the proportion of high frequencies during the "loud" parts, I
suppose to give the listener the illusion that it's really getting louder.
The DRC alone is bad enough, but in addition it's as though someone is
winding the treble knob up and down throughout. The result is truly
ghastly.
These days people are paying a fortune for hi-fi home theatre systems, but
the channels continue to transmit pure crap. Why do they do it?

David
=============
Hi D,

DRC is applied so that there are no 'quiet' parts in the broadcast, always
to be in your face, so that the listener will *always* be able to hear the
signal.

Many classical recordings have extremely quiet parts, often inaudible in a
moving vehicle or environments where there is background noise (restaurants,
lobbies, elevators). They figure if you can't hear it, you'll tune out.

The frequency wah wah you're hearing could be atmospheric, could be phasing
from reflected sigs due to your location (buildings/mountains), could be
that AFC is not engaged...

Could be a phenom of your speakers, how does it muster on headphones?

-bg-

www.thelittlecanadaheadphoneband.ca

David White wrote:
These days people are paying a fortune for hi-fi home theatre systems, but
the channels continue to transmit pure crap. Why do they do it?

Because it's louder. It needs to be louder. And if they didn't use all that
compression, they'd have to adjust the gain and stuff.
--scott
--
"C'est un Nagra. C'est suisse, et tres, tres precis."

David White wrote:

It seems to me that the biggest difference in sound quality between a
released CD or DVD and an analog stereo TV or radio broadcast is the
sometimes severe DRC applied to the broadcast. I can understand it if the
form of transmission makes it necessary, but I don't understand why cable TV
channels do it. For example, the Ovation arts channel in Australia transmits
orchestral music with _extremely_ severe DRC. They also seem to artificially
increase the proportion of high frequencies during the "loud" parts, I
suppose to give the listener the illusion that it's really getting louder.
The DRC alone is bad enough, but in addition it's as though someone is
winding the treble knob up and down throughout. The result is truly ghastly.
These days people are paying a fortune for hi-fi home theatre systems, but
the channels continue to transmit pure crap. Why do they do it?

Out of habit.


Graham

David White wrote:

I certainly hope the digital broadcast age will fix this blight on broadcast
sound quality once and for all.

Don't bet on it !


Graham

"David White" wrote in message
news
" ~ rob ~" wrote in message
news:Ax8Bb.611354$pl3.406764@pd7tw3no...

Hi D,

DRC is applied so that there are no 'quiet' parts in the broadcast,
always
to be in your face, so that the listener will *always* be able to hear
the
signal.

Many classical recordings have extremely quiet parts, often inaudible in
a
moving vehicle or environments where there is background noise
(restaurants,
lobbies, elevators). They figure if you can't hear it, you'll tune out.

Well, sometimes Ovation has broadcast the same program that was previously
broadcast (via the air) on the Australian Broadcast Corporation's TV
channel. The ABC is the government broadcaster (like the BBC in Britain
and
CBC in Canada). It has powerful transmitters all over the country and much
higher broadcast quality standards. It does not seem to do DRC on music
broadcasts. On the ABC, very quiet passages in the music are very quiet in
the broadcast. If it's okay for them, then why not the cable channels too?
Remember that CDs and DVDs usually don't have DRC and people can hear the
quiet passages.

The frequency wah wah you're hearing could be atmospheric, could be
phasing
from reflected sigs due to your location (buildings/mountains), could be
that AFC is not engaged...

No, it's definitely being transmitted that way. You can tell just from the
sound that it's deliberate, but you can also tell from the comparison
between the ABC and Ovation for the same program (I have stereo recordings
from both).

Could be a phenom of your speakers, how does it muster on headphones?

It's the same on speakers and headphones. I've only noticed this
phenomenon
on Ovation, and it's the same on all the music they broadcast.

I certainly hope the digital broadcast age will fix this blight on
broadcast
sound quality once and for all.

David
===============
'They' likely think of their sig going into noisy bars, high background
noise; and motorcyclists.....

eh?

-bg-

www.thelittlecanadaheadphoneband.ca

" ~ rob ~" wrote in message
news:TsbBb.613173$pl3.51639@pd7tw3no...

'They' likely think of their sig going into noisy bars, high background
noise; and motorcyclists.....

eh?

Hmm, somehow I don't associate noisy bars and motorcyclists with Beethoven's
Pastoral symphony and the like.

David

"Scott Dorsey" wrote in message
...
David White wrote:
These days people are paying a fortune for hi-fi home theatre systems,
but
the channels continue to transmit pure crap. Why do they do it?

Because it's louder. It needs to be louder. And if they didn't use all
that
compression, they'd have to adjust the gain and stuff.
--scott
--
"C'est un Nagra. C'est suisse, et tres, tres precis."


when radio guys evaluate TV audio it has always seemed that the TV people
only notice audio when its is missing.

the audio component of a TV signal is very much like a FM broadcast signal
and is processes in a similar way. one the most common processors is the
optimod-TV. you can find the current version the 8182A under products at
http://www.orban.com/

now look at the problems of a cable company... they would need one for each
audio stream.. can you imagine a room with 400 or so of these in racks?

~ rob ~ wrote:

DRC is applied so that there are no 'quiet' parts in the broadcast, always
to be in your face, so that the listener will *always* be able to hear the
signal.

In this day and age playback equipment for use in such circumstances has
its own dynamic range reduction options. There is no need to decide on
behalf of the listener.

The frequency wah wah you're hearing could be atmospheric, could be phasing
from reflected sigs due to your location (buildings/mountains), could be
that AFC is not engaged...

The questionee appears to be on cable.

Could be a phenom of your speakers, how does it muster on headphones?

Cable FM takes it down from the ether or gets it piped and then converts
to digital, whereafter they bitreduce suitably to fit the available
bandwidth. It then gets transmitted digitally to the local area where it
is converted back to analog and used to modulate a FM tranmitter wired
to the cabling.
This well thought out process ensures that whatever sonic qualities the
original FM broadcast may have had are lost and introduces multiple ways
in which the cable distributer can get things wrong.

Once upon a time, on a day I was severely bored, I sat down with my DAT
and made a list of the modulation errors on cable FM and Television
based on the asumption that any sane station, whatever their loudness
policy might be, would modulate to 100 percent occasionally. Some
channels were consistently clipped and some channels never exceeded -10
dB.

-bg-

www.thelittlecanadaheadphoneband.ca


Kind regards

Peter Larsen

--
************************************************** ***********
* My site is at: http://www.muyiovatki.dk *
************************************************** ***********

"Peter Larsen" wrote in message
...
Cable FM takes it down from the ether or gets it piped and then converts
to digital, whereafter they bitreduce suitably to fit the available
bandwidth. It then gets transmitted digitally to the local area where it
is converted back to analog and used to modulate a FM tranmitter wired
to the cabling.
This well thought out process ensures that whatever sonic qualities the
original FM broadcast may have had are lost and introduces multiple ways
in which the cable distributer can get things wrong.

This is interesting. As I mentioned elsewhere, the ABC in Australia does not
seem to do any DRC on its free-to-air TV broadcasts. The cable channels also
re-transmit the free-to-air channels, for the benefit of those in
difficult-reception areas. I've wondered whether bandwidth issues were
involved in Ovation's appalling sound quality, but, as far as I can tell,
the ABC signal re-transmitted by cable is exactly the same as the
free-to-air signal. This suggests that the cable is capable of supporting
sound with wide dynamic range.

David

David White wrote:

This is interesting. As I mentioned elsewhere, the ABC in Australia does not
seem to do any DRC on its free-to-air TV broadcasts. The cable channels also
re-transmit the free-to-air channels, for the benefit of those in
difficult-reception areas. I've wondered whether bandwidth issues were
involved in Ovation's appalling sound quality, but, as far as I can tell,
the ABC signal re-transmitted by cable is exactly the same as the
free-to-air signal. This suggests that the cable is capable of supporting
sound with wide dynamic range.

Yes, but this requires someone actually setting the gains at the headend
properly.

In the US, video people don't pay much attention to audio, and they rely
on AVC units to set levels rather than line everything up by hand. So
you may have a show which is produced in a studio where the output of the
console goes through an AVC unit to tape, then the tape is edited in
an editing suite where everything goes through an AVC unit, and then
the edited tape goes to the network where they play it back through an
AVC system to the switching system, then through an AVC unit to the bird,
and then the local network affiliate takes it off the bird, through an
AVC unit to their switch matrix, then to the transmitter where it goes
through an AVC unit and some limiting. Then the cable folks pick it up
off the air and run it through an AVC unit to the modulator.

Needless to say, what this does to dynamics is not good.
--scott


--
"C'est un Nagra. C'est suisse, et tres, tres precis."

"tim perry" wrote in news:eccBb.9113
:


"Scott Dorsey" wrote in message
...
David White wrote:
These days people are paying a fortune for hi-fi home theatre systems,
but
the channels continue to transmit pure crap. Why do they do it?

Because it's louder. It needs to be louder. And if they didn't use
all
that
compression, they'd have to adjust the gain and stuff.
--scott
--
"C'est un Nagra. C'est suisse, et tres, tres precis."


when radio guys evaluate TV audio it has always seemed that the TV
people
only notice audio when its is missing.


You are absolutely correct. For months there was a Chicago TV station
that played tapes on a terribly misaligned machine. The time code track
on the tapes was plainly heard in the audio.

r


--
Nothing beats the bandwidth of a station wagon filled with DLT tapes.