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Jason[_14_] Jason[_14_] is offline
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Default Clipping on professionally produced CD's



I was listening to a Paul Simon CD (The Best Of..) and thought I'd
"look" at some of the tracks in Audition. To my surprise, two of the
three I um auditioned clipped in a number of spots. I haven't done this
with other CD's and am surprised at this; is it common? FWIW, I listened
carefully with headphones and couldn't hear evidence of clipping. Perhaps
the pros know something I don't (falls over laughing hysterically).
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"Jason" wrote in message
...
I was listening to a Paul Simon CD (The Best Of..) and thought I'd
"look" at some of the tracks in Audition. To my surprise, two of the
three I um auditioned clipped in a number of spots. I haven't done this
with other CD's and am surprised at this; is it common?


Sure is, try a few hundred pop CD's and see for youself!

FWIW, I listened
carefully with headphones and couldn't hear evidence of clipping.


Maybe not if it's fairly minor. Now try some Lady GaGa, Katy Perry etc. :-)

Trevor.


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Scott Dorsey Scott Dorsey is offline
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Default Clipping on professionally produced CD's

Jason wrote:

I was listening to a Paul Simon CD (The Best Of..) and thought I'd
"look" at some of the tracks in Audition. To my surprise, two of the
three I um auditioned clipped in a number of spots. I haven't done this
with other CD's and am surprised at this; is it common? FWIW, I listened
carefully with headphones and couldn't hear evidence of clipping. Perhaps
the pros know something I don't (falls over laughing hysterically).


Yes, it's common.
Yes, it sounds godawful on good monitors.

Oh, well.
--scott

--
"C'est un Nagra. C'est suisse, et tres, tres precis."
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[email protected] sgordon@changethisparttohardbat.com is offline
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Default Clipping on professionally produced CD's

Look up "loudness wars".

Jason wrote:
: I was listening to a Paul Simon CD (The Best Of..) and thought I'd
: "look" at some of the tracks in Audition. To my surprise, two of the
: three I um auditioned clipped in a number of spots. I haven't done this
: with other CD's and am surprised at this; is it common? FWIW, I listened
: carefully with headphones and couldn't hear evidence of clipping. Perhaps
: the pros know something I don't (falls over laughing hysterically).
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vdubreeze vdubreeze is offline
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Default Clipping on professionally produced CD's

On Jan 18, 9:02*pm, "Trevor" wrote:


FWIW, I listened
carefully with headphones and couldn't hear evidence of clipping.


Maybe not if it's fairly minor.



Also, are we talking about the clip indicator (as opposed to manually
checking the file)? If an indicator is set to light up at a single
sample clip, that could explain why it's not perceptible even under
headphones. Isn't it acknowledged that an isolated single sample clip
isn't detectable, (though a few consecutive/contiguous samples
obviously would be)?

Anyway, it's pretty common for a commercial CD to show overs on a
user's computer though the person who mastered it will insist there
were no overs in mastering and that it was. Google took a break from
SOPA blackouting and yielded a few, including this one where the user
also was in Audition:

http://www.gearslutz.com/board/maste...questions.html

Here the masterer casts aspersion on Audition's metering, which I
always took to be a good meter, but anyway, it's an example of
something showing clips in Audition and the creator of the file is
saying there are no actual overs, FWIW.


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Default Clipping on professionally produced CD's

On 19/01/2012 5:02 PM, vdubreeze wrote:
On Jan 18, 9:02 pm, "Trevor" wrote:
FWIW, I listened
carefully with headphones and couldn't hear evidence of clipping.

Maybe not if it's fairly minor.



Also, are we talking about the clip indicator (as opposed to manually
checking the file)? If an indicator is set to light up at a single
sample clip, that could explain why it's not perceptible even under
headphones. Isn't it acknowledged that an isolated single sample
clip
isn't detectable, (though a few consecutive/contiguous samples
obviously would be)?

Anyway, it's pretty common for a commercial CD to show overs on a
user's computer though the person who mastered it will insist there
were no overs in mastering. Google took a break from
SOPA blackouting and yielded a few, including this one where the user
also was in Audition:

http://www.gearslutz.com/board/maste...iley-cyrus-see...
Here the masterer casts aspersion on Audition's metering, which I
always took to be a good meter, but anyway, it's an example of
something showing clips in Audition and the creator of the file is
saying there are no actual overs, FWIW.


'Clipping' is not the same as 'overs', you can have a brick wall limiter
set to -6dBFS and slam it so the waveform is clipped, even though it is
-6dBFS. So there aren't any overs, just squared off waveforms.
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Anahata Anahata is offline
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Default Clipping on professionally produced CD's

On Thu, 19 Jan 2012 19:36:45 +1100, swanny wrote:

'Clipping' is not the same as 'overs',


In theory clipping could be done artificially at less than 0dBFS, but I
don't think that's the issue here.

you can have a brick wall limiter
set to -6dBFS and slam it so the waveform is clipped, even though it is
-6dBFS. So there aren't any overs, just squared off waveforms.


Brick wall limiting doesn't work by clipping the waveform. It's a
compressor with infinite compression ratio and very short attack and
release times. The short attack time will cause a little distortion, but
far less than pure waveform clipping.

--
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William Sommerwerck William Sommerwerck is offline
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Default Clipping on professionally produced CD's

Many, many years ago, "Stereo Review" ran listening tests, and determined
that 1 to 2dB of amplifier clipping was audible on solo violin.


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"Arny Krueger" wrote in message
...
"William Sommerwerck" wrote in message
...


Many, many years ago, "Stereo Review" ran listening tests, and
determined that 1 to 2dB of amplifier clipping was audible on solo

violin.

Probably true on a steady violin tone. Step back a bit for a recording of
a string quartet, and more clipping can probably sneak past the ear.


Probably true, but there's plenty of solo-violin music.


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"William Sommerwerck" wrote in message
...
Many, many years ago, "Stereo Review" ran listening tests, and determined
that 1 to 2dB of amplifier clipping was audible on solo violin.


Probably true on a steady violin tone. Step back a bit for a recording of a
string quartet, and more clipping can probably sneak past the ear.




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"Scott Dorsey" wrote in message
...
William Sommerwerck wrote:


Many, many years ago, "Stereo Review" ran listening tests, and
determined that 1 to 2dB of amplifier clipping was audible on solo

violin.

Yes. But on the other hand, you can have pretty substantial clipping
on one side of a trumpet waveform and not notice it much.


To paraphrase Alice... "Which side is not so noticeable?" (The trumpet's
waveform is quite asymmetrical.)


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William Sommerwerck wrote:
Many, many years ago, "Stereo Review" ran listening tests, and determined
that 1 to 2dB of amplifier clipping was audible on solo violin.


Yes. But on the other hand, you can have pretty substantial clipping on
one side of a trumpet waveform and not notice it much.
--scott
--
"C'est un Nagra. C'est suisse, et tres, tres precis."
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"William Sommerwerck" wrote in message
...
"Arny Krueger" wrote in message
...
"William Sommerwerck" wrote in message
...


Many, many years ago, "Stereo Review" ran listening tests, and
determined that 1 to 2dB of amplifier clipping was audible on solo

violin.

Probably true on a steady violin tone. Step back a bit for a recording of
a string quartet, and more clipping can probably sneak past the ear.


Probably true, but there's plenty of solo-violin music.


Unfortunately :-)

Poly


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"vdubreeze" wrote in message
...

Anyway, it's pretty common for a commercial CD to show overs on a
user's computer though the person who mastered it will insist there
were no overs in mastering and that it was. Google took a break from
SOPA blackouting and yielded a few, including this one where the user
also was in Audition:

http://www.gearslutz.com/board/maste...questions.html

Here the masterer casts aspersion on Audition's metering, which I
always took to be a good meter, but anyway, it's an example of
something showing clips in Audition and the creator of the file is
saying there are no actual overs, FWIW.

---------------------

What a load of crap, there is no "metering" necessary to rip a CD and
display the clipping in any wave editor. And any mastering engineer who
can't tell the CD is really clipped should be out of a job for being
technologically incompetent.

Trevor.


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Default Clipping on professionally produced CD's


"swanny" wrote in message
nd.com...
'Clipping' is not the same as 'overs', you can have a brick wall limiter
set to -6dBFS and slam it so the waveform is clipped, even though it is
-6dBFS. So there aren't any overs, just squared off waveforms.


Which are still clipped regardless of the final peak level.

Trevor.






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"Anahata" wrote in message
o.uk...
Brick wall limiting doesn't work by clipping the waveform. It's a
compressor with infinite compression ratio and very short attack and
release times. The short attack time will cause a little distortion, but
far less than pure waveform clipping.


A perfect brick wall limiter with infinite compression and infinitely fast
attack *IS* simply clipping, pure and simple.

Trevor.


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"William Sommerwerck" wrote in message
...
"Scott Dorsey" wrote in message
...
William Sommerwerck wrote:


Many, many years ago, "Stereo Review" ran listening tests, and
determined that 1 to 2dB of amplifier clipping was audible on solo

violin.

Yes. But on the other hand, you can have pretty substantial clipping
on one side of a trumpet waveform and not notice it much.


To paraphrase Alice... "Which side is not so noticeable?" (The trumpet's
waveform is quite asymmetrical.)


Right, but you are always going to get clipping on the same side before the
other, and then you get clipping on BOTH sides when it's well and truly
overloaded.
(unless you have a serious DC offset problem :-)

Trevor.


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Default Clipping on professionally produced CD's

In article , says...

"vdubreeze" wrote in message
...

Anyway, it's pretty common for a commercial CD to show overs on a
user's computer though the person who mastered it will insist there
were no overs in mastering and that it was. Google took a break from
SOPA blackouting and yielded a few, including this one where the user
also was in Audition:

http://www.gearslutz.com/board/maste...questions.html

Here the masterer casts aspersion on Audition's metering, which I
always took to be a good meter, but anyway, it's an example of
something showing clips in Audition and the creator of the file is
saying there are no actual overs, FWIW.

---------------------

What a load of crap, there is no "metering" necessary to rip a CD and
display the clipping in any wave editor. And any mastering engineer who


can't tell the CD is really clipped should be out of a job for being
technologically incompetent.

Trevor.


In addition to realtime meters, Audition has a function that will scan a
selection--whole file in this case--and produce amplitude statistics.
From "Late in the Evening" we have:



Front Left Front Right
Peak Amplitude: 0.00 dB 0.00 dB
Maximum Sample Value: 32767 32767
Minimum Sample Value: -32768 -32768
Possibly Clipped Samples: 48 76
Total RMS Amplitude: -14.62 dB -15.01 dB
Maximum RMS Amplitude: -5.83 dB -6.52 dB
Minimum RMS Amplitude: -76.58 dB -77.96 dB
Average RMS Amplitude: -18.01 dB -18.51 dB
DC Offset: 0.00 % 0.00 %
Measured Bit Depth: 16 16
Dynamic Range: 70.75 dB 71.44 dB
Dynamic Range Used: 60.10 dB 61.60 dB
Perceived Loudness: -12.52 dB -13.17 dB
Perceived Eq Loudness: -8.82 dB -9.16 dB

0dB = FS Square Wave
Using RMS Window of 50.00 ms
Account for DC = true


This must have predated the Loudness Wars.


Jason
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Scott Dorsey Scott Dorsey is offline
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Default Clipping on professionally produced CD's

In article , Trevor wrote:

Here the masterer casts aspersion on Audition's metering, which I
always took to be a good meter, but anyway, it's an example of
something showing clips in Audition and the creator of the file is
saying there are no actual overs, FWIW.

What a load of crap, there is no "metering" necessary to rip a CD and
display the clipping in any wave editor. And any mastering engineer who
can't tell the CD is really clipped should be out of a job for being
technologically incompetent.


Hint: there is no one definition for an "over" because you can in fact
not measure how far over the signal has gone once it has clipped. All
you can do is decide how many consecutive FS samples you consider an over,
and not everybody sets the limit at the same place.
--scott

--
"C'est un Nagra. C'est suisse, et tres, tres precis."
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Default Clipping on professionally produced CD's

On Jan 19, 9:23*pm, (Scott Dorsey) wrote:
In article , Trevor wrote:

Here the masterer casts aspersion on Audition's metering, which I
always took to be a good meter, but anyway, it's an example of
something showing clips in Audition and the creator of the file is
saying there are no actual overs, FWIW.


What a load of crap, there is no "metering" necessary to rip a CD and
display the clipping in any wave editor. And any mastering engineer who
can't tell the CD is really clipped should be out of a job for being
technologically incompetent.


Hint: there is no one definition for an "over" because you can in fact
not measure how far over the signal has gone once it has clipped. *All
you can do is decide how many consecutive FS samples you consider an over,
and not everybody sets the limit at the same place.
--scott

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


also there is NOT an exact 1 to 1 correspondence between the digital
sample values and the reconstructed analog waveform. It is easy to
demonstrate an un-clipped waveform that has no digital samples over
-1dBFS and still the analog reconstructed waveform exceeds 0 dBFS by a
few dB and is not necessarily clipped if the analog circuits have
sufficient headroom.

So that raises a question about the formal standard for metering
relative to 0 dBFS.

Is the formal definition of level refer to the waveform in the analog
domain or the samples in the digital domain. There was a discussion a
while ago, I think it was here on RAP, about the several dB possible
difference.

Mark




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Frank Stearns Frank Stearns is offline
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(Scott Dorsey) writes:

In article , Trevor wrote:

Here the masterer casts aspersion on Audition's metering, which I
always took to be a good meter, but anyway, it's an example of
something showing clips in Audition and the creator of the file is
saying there are no actual overs, FWIW.

What a load of crap, there is no "metering" necessary to rip a CD and
display the clipping in any wave editor. And any mastering engineer who
can't tell the CD is really clipped should be out of a job for being
technologically incompetent.


Hint: there is no one definition for an "over" because you can in fact
not measure how far over the signal has gone once it has clipped. All
you can do is decide how many consecutive FS samples you consider an over,
and not everybody sets the limit at the same place.
--scott


Indeed; some tools let you adjust how many FS samples in a row determine a clip.


For the post side of things I've been using the TL Master meter plug-in in Protools
8 -- it's quite a useful tool.

It meters at 8x oversample and thus I assume it can give an idea of just how far
over you've gone. It keeps a running history of where the signal went beyond FS, and
just how far. (I'd be interested to know how it calculates just how far over FS
things have gone, but it appears to do so, to the fractional dB.)

In addition, the visual meters are hugely exaggerated in their scale from -6.02 to
+6.02 -- makes it easy to see how you're tickling (or assaulting) that last bit. (If
the project is going out for real mastering, I rarely get close to FS. But if mix
and master are rolled into one for the starving classical clients, this is a useful
tool to have.)

It's interesting to see the stuff that gets through without lighting any clip
indicators on regular PT and PT plug-in metering, whereas this tool will show
that indeed, things went over.

This assumes, of course, it's properly calibrated and their arithmetic is
correct...

Frank
Mobile Audio
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Default Clipping on professionally produced CD's

Trevor wrote:
: A perfect brick wall limiter with infinite compression and infinitely fast
: attack *IS* simply clipping, pure and simple.

Not if you perform the compression by identifying the overs, reaching
outward to the nearest zero-crossings, and reduce the volume of that
small portion of the wave. The wave still retains its original curvature.
There is software for doing that. (done too aggressively still results
eventually in clipping-like artifacts, though, even if the waveform doesn't
appear to have been clipped - so whether or not that qualifies as "clipping"
could be a matter of semantics)

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On Jan 19, 7:08*pm, "Trevor" wrote:
"Anahata" wrote in message

o.uk...

Brick wall limiting doesn't work by clipping the waveform. It's a
compressor with infinite compression ratio and very short attack and
release times. The short attack time will cause a little distortion, but
far less than pure waveform clipping.


A perfect brick wall limiter with infinite compression and infinitely fast
attack *IS* simply clipping, pure and simple.

Trevor.




This is getting into semantics. But it's not really the same. A
brick wall limiter can yield the same resulting looking waveform, but
many would disagree that smashing and flattening the waveform is the
same as clipping.

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"Scott Dorsey" wrote in message
...
In article , Trevor
wrote:
What a load of crap, there is no "metering" necessary to rip a CD and
display the clipping in any wave editor. And any mastering engineer who
can't tell the CD is really clipped should be out of a job for being
technologically incompetent.


Hint: there is no one definition for an "over" because you can in fact
not measure how far over the signal has gone once it has clipped.


Don't need to, more than 3 or so consecutive samples at dFS is usually
considered over, (unless it's a test recording of a square wave) how far
over is irrelevent to the definition (if not the sound), it's still clipped.


All
you can do is decide how many consecutive FS samples you consider an over,
and not everybody sets the limit at the same place.


Right, have a look at some modern CD's with 100's of consecutive samples at
dFS and pretend it's not over if YOU want!
That's called the osterich concept :-)

Trevor.


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"Mark" wrote in message
...
also there is NOT an exact 1 to 1 correspondence between the digital

sample values and the reconstructed analog waveform. It is easy to
demonstrate an un-clipped waveform that has no digital samples over
-1dBFS and still the analog reconstructed waveform exceeds 0 dBFS by a
few dB and is not necessarily clipped if the analog circuits have
sufficient headroom.



Irrelevent since we are talking about the digital samples on a CD being
clipped already.

Trevor.




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"Frank Stearns" wrote in message
acquisition...
(I'd be interested to know how it calculates just how far over FS
things have gone, but it appears to do so, to the fractional dB.)


It's probably the same bezier interpolation estimation that "declipping"
tools use.


This assumes, of course, it's properly calibrated and their arithmetic is
correct...


As always!

Trevor.


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wrote in message
...
Trevor wrote:
: A perfect brick wall limiter with infinite compression and infinitely
fast
: attack *IS* simply clipping, pure and simple.

Not if you perform the compression by identifying the overs, reaching
outward to the nearest zero-crossings, and reduce the volume of that
small portion of the wave. The wave still retains its original curvature.


It's NOT then a BRICK WALL limiter by definition!

Trevor.


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"vdubreeze" wrote in message
...
On Jan 19, 7:08 pm, "Trevor" wrote:
"Anahata" wrote in message
o.uk...
Brick wall limiting doesn't work by clipping the waveform. It's a
compressor with infinite compression ratio and very short attack and
release times. The short attack time will cause a little distortion, but
far less than pure waveform clipping.


A perfect brick wall limiter with infinite compression and infinitely fast
attack *IS* simply clipping, pure and simple.



}This is getting into semantics. But it's not really the same. A
}brick wall limiter can yield the same resulting looking waveform, but
}many would disagree that smashing and flattening the waveform is the
}same as clipping.


That's the problem, they simply don't realise (or admit) it **IS** the same
as clipping given a perfect brick wall limiter.
Given a less than perfect brick wall limiter (as in the real world), it will
be somewhat less than perfect clipping, and may or may not sound any better
than clipping. A brick wall limiters main function is equipment protection,
not music protection after all, we have proper compressors for that.

Trevor.



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On Fri, 20 Jan 2012 16:26:54 +1100, Trevor wrote:

"Scott Dorsey" wrote in message


Hint: there is no one definition for an "over" because you can in fact
not measure how far over the signal has gone once it has clipped.


Don't need to, more than 3 or so consecutive samples at dFS is usually
considered over


Steady on - your qualification of "usually" corresponds with Scott's
"there is no one definition". Some meters use 3 samples, some use more,
some use less.

If you want to nitpick about whether clipping occurred or not, it isn't
always easy to define. For instance it's quite possible for two
consecutive samples at full scale accurately to represent a peak between
those samples which was over full scale value. Whether that results in
actual distortion on output depends on whether the reconstruction filter
can cope with levels over FS. That's one reason why people aim for
anything between -0.1dBFS and -1dBFS maximum for peak levels.

Of course hundreds of samples in a row at FS is clipped - nobody's
disputing that, but how often is it that bad with commercial CDs?

--
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On Fri, 20 Jan 2012 16:42:42 +1100, Trevor wrote:

That's the problem, they simply don't realise (or admit) it **IS** the
same as clipping given a perfect brick wall limiter.


Feeding a sine wave into a "brick wall limiter" over the limiter's
threshold produces a sine wave attenuated so the peaks just reach the
threshold level.

If you think it produces a waveform with clipped peaks, you are simply
wrong. Even with infinitely fast attack (which is possible in digital
processing) any device or plugin calling itself a limiter does not also
have infinitely fast release.

--
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-+- http://www.treewind.co.uk
Home: 01638 720444 Mob: 07976 263827


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"Jason" wrote in message
...
In article , says...

"vdubreeze" wrote in message
...

Anyway, it's pretty common for a commercial CD to show overs on a
user's computer though the person who mastered it will insist there
were no overs in mastering and that it was. Google took a break from
SOPA blackouting and yielded a few, including this one where the user
also was in Audition:

http://www.gearslutz.com/board/maste...questions.html

Here the masterer casts aspersion on Audition's metering, which I
always took to be a good meter, but anyway, it's an example of
something showing clips in Audition and the creator of the file is
saying there are no actual overs, FWIW.

---------------------

What a load of crap, there is no "metering" necessary to rip a CD and
display the clipping in any wave editor. And any mastering engineer who


can't tell the CD is really clipped should be out of a job for being
technologically incompetent.

Trevor.


In addition to realtime meters, Audition has a function that will scan a
selection--whole file in this case--and produce amplitude statistics.
From "Late in the Evening" we have:



Front Left Front Right
Peak Amplitude: 0.00 dB 0.00 dB
Maximum Sample Value: 32767 32767
Minimum Sample Value: -32768 -32768
Possibly Clipped Samples: 48 76



That few clipped samples in a good-sized musical selection is probably not
audible.

There are 41,000 samples in every second of the song.


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Scott Dorsey Scott Dorsey is offline
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Default Clipping on professionally produced CD's

Mark wrote:

Is the formal definition of level refer to the waveform in the analog
domain or the samples in the digital domain. There was a discussion a
while ago, I think it was here on RAP, about the several dB possible
difference.


It is indeed the samples in the digital domain that are checked.

For a few years after I started recording digitally, I did not have proper
digital metering; most of the DAT machines had meters with very low
resolution. Consequently, I used a peak-reading circuit on the analogue
side, which I could never, ever get to quite agree with the digital
bitscope values.

It got even worse when using emphasis, which actually was advantagous back
then because converters were so bad... the analogue metering had emphasis
but it never _quite_ matched to within a fraction of a dB to to the recorder
de-emphasis. (You want to meter the emphasized digital values.)

Then I spent way too much money and bought an RTW and it was like a miracle
that actually knew precisely where my levels were at all times.
--scott


--
"C'est un Nagra. C'est suisse, et tres, tres precis."
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Scott Dorsey Scott Dorsey is offline
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Default Clipping on professionally produced CD's

In article , Trevor wrote:

"Scott Dorsey" wrote in message
...
In article , Trevor
wrote:
What a load of crap, there is no "metering" necessary to rip a CD and
display the clipping in any wave editor. And any mastering engineer who
can't tell the CD is really clipped should be out of a job for being
technologically incompetent.


Hint: there is no one definition for an "over" because you can in fact
not measure how far over the signal has gone once it has clipped.


Don't need to, more than 3 or so consecutive samples at dFS is usually
considered over, (unless it's a test recording of a square wave) how far
over is irrelevent to the definition (if not the sound), it's still clipped.


Strange, the Tascam machines don't light the over light until five consecutive
FS samples occur. And my RTW bench meter lights the over light when only two
consecutive ones do.
--scott

--
"C'est un Nagra. C'est suisse, et tres, tres precis."
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ChrisCoaster ChrisCoaster is offline
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Default Clipping on professionally produced CD's

On Jan 18, 8:46*pm, Jason wrote:
I was listening to a Paul Simon CD (The Best Of..) and thought I'd
"look" at some of the tracks in Audition. To my surprise, two of the
three I um auditioned clipped in a number of spots. I haven't done this
with other CD's and am surprised at this; is it common? FWIW, I listened
carefully with headphones and couldn't hear evidence of clipping. Perhaps
the pros know something I don't (falls over laughing hysterically).

______________
Metallica's "Death Magnetic"(2008) album is considered one of the
loudest records ever produced and the most blatent example of what the
loudness war is doing to commercial recorded sound.
I'm surprised until now it has not been mentioned in this very good
thread.

-ChrisCoaster


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Arny Krueger[_4_] Arny Krueger[_4_] is offline
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"Jason" wrote in message
...
In article ,
says...

"Jason" wrote in message
...
In article ,
says...

"vdubreeze" wrote in message
...


Possibly Clipped Samples: 48 76



That few clipped samples in a good-sized musical selection is probably
not
audible.

There are 41,000 samples in every second of the song.


For sure! I was just surprised that there were -any-.


There may not have actually been any. We can never know for sure if a given
piece of music was clipped. All we know for absolute sure is that there are
samples at +/- FS.

The appearance of clipped waves when the clipping is severe is very
characteristic and obvious. Inferring clipping when there are thousands or
millions of clipped samples is a very sure inference, but its nevertheless
an inference.

When you have only a few dozen samples at +/- FS over a reasonably long
recording, the inference that the recording was clipped is really pretty
weak. Concluding that the recording sounds bad due to clipping is
exceedingly weak. It may sound bad, but the samples at +/- FS are not
sufficient to produce the observed sound quality. The problem was highly
probably something else. If all that is questionable about this recording is
124 more or less samples at +/- FS, then so what?


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Arkansan Raider Arkansan Raider is offline
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polymod wrote:
"William Sommerwerck" wrote in message
...
"Arny Krueger" wrote in message
...
"William Sommerwerck" wrote in message
...
Many, many years ago, "Stereo Review" ran listening tests, and
determined that 1 to 2dB of amplifier clipping was audible on solo

violin.

Probably true on a steady violin tone. Step back a bit for a recording of
a string quartet, and more clipping can probably sneak past the ear.

Probably true, but there's plenty of solo-violin music.


Unfortunately :-)

Poly



Now that's just mean. ;^)

---Jeff
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Trevor Trevor is offline
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"Anahata" wrote in message
o.uk...
Hint: there is no one definition for an "over" because you can in fact
not measure how far over the signal has gone once it has clipped.


Don't need to, more than 3 or so consecutive samples at dFS is usually
considered over


Steady on - your qualification of "usually" corresponds with Scott's
"there is no one definition". Some meters use 3 samples, some use more,
some use less.


Right, 3 OR SO. Anyone who uses a hundred or more is simply a fool.



If you want to nitpick about whether clipping occurred or not, it isn't
always easy to define. For instance it's quite possible for two
consecutive samples at full scale accurately to represent a peak between
those samples which was over full scale value.


Right, 3 or so, not 2.


Of course hundreds of samples in a row at FS is clipped - nobody's
disputing that, but how often is it that bad with commercial CDs?


FAR too often, and unnecessary. Obviously you haven't actually looked at
Katy Perry, Britney Spears, Lady GaGa, Miley Cyrus etc. CD's. And they're
just of few of the BIG selling artists.

Trevor.


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"Anahata" wrote in message
o.uk...
That's the problem, they simply don't realise (or admit) it **IS** the
same as clipping given a perfect brick wall limiter.


Feeding a sine wave into a "brick wall limiter" over the limiter's
threshold produces a sine wave attenuated so the peaks just reach the
threshold level.


Better look up what a "brick wall" limiter actually is.
Hint: there's a good clue in the name!


If you think it produces a waveform with clipped peaks, you are simply
wrong.


Or YOU are. It simply sets the clipping point where you want it.

Even with infinitely fast attack (which is possible in digital
processing) any device or plugin calling itself a limiter does not also
have infinitely fast release.


Right, but that doesn't stop clipping.
And lets be clear here, I never said ANY limiter, I said BRICK WALL LIMITER,
get it yet?

Trevor.




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"Arny Krueger" wrote in message
...
There may not have actually been any. We can never know for sure if a
given piece of music was clipped. All we know for absolute sure is that
there are samples at +/- FS.

The appearance of clipped waves when the clipping is severe is very
characteristic and obvious. Inferring clipping when there are thousands or
millions of clipped samples is a very sure inference, but its nevertheless
an inference.

When you have only a few dozen samples at +/- FS over a reasonably long
recording, the inference that the recording was clipped is really pretty
weak. Concluding that the recording sounds bad due to clipping is
exceedingly weak. It may sound bad, but the samples at +/- FS are not
sufficient to produce the observed sound quality. The problem was highly
probably something else. If all that is questionable about this recording
is 124 more or less samples at +/- FS, then so what?




Whilst that piece of music is hardly likely to be audibly affected by
clipping, LOOKING at a waveform in a wave editor will tell you if there is
clipping or not. No need to measure samples and INFER anything.

Trevor.


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