[Mxsmanic]

Scott Dorsey writes:

_all_ clipping is to some extent shaped like a square wave. As soon as you
get even a little bit of clipping, you start getting huge amounts of odd
harmonics popping up, just like a square wave.

Cool, at least I'm on the right track. So how come clipping often sounds
subjectively so much worse than a square wave? Does the actual waveform after
conversion to digital look a lot messier than a square wave because of
problems with the conversion, or does the conversion back to analog handle the
square wave at 0 dB poorly when it's converted back to an analog waveform, or
what? Or is it just an auditory illusion even though it really is a square
wave when it comes back out?

[Trevor]

"Peter Larsen" wrote in message
k...
Mxsmanic wrote:
Am I mistaken, or would the worst case of clipping be shaped
essentially like a square wave? That is, a nearly vertical component
to the waveform, with an instant transition to a perfectly horizontal
component, followed by an instant transition to a nearly vertical
component again. That would seem to be the most extreme case of
clipping imaginable. Which in turn implies that the worst clipping in
digital audio would sound like a square wave.

In theory, yes.

Clean diode action clips up to a couple of milliseconds are not at all or
only marginally obvious but not all clipping is clean. My understanding is
that complications can include polarity reversals and burst of noise.

I have a poweramp (Audire dual 120 watts, great sound & wonderful deep and
powerfull bass) - now in repair queue with a silent right channel - that
for years added a burst of noise whenever it clipped that now silent
channel, conceivably the warranty refill of brown smoke wasn't done
properly or perhaps the designers aim for megahz bandwidth was plain
silly. I had asked for a known bandwidth reduction fix to be implemnted on
it when the right channel got new output transistors ... it either wasn't
done or wasn't enough or something else that was marginal ex works was
overlooked in the repair. Never a problem with left channel, including
clipping as gently as clipping should be.

Well it's not really "clipping" by definition if it's gentle. But that seems
to be the major problem, everyone has their own definition. The amplifier
may distort gradually, but eventually hits the maximum rail voltage where it
clips. (the rail voltage may change a bit of course with capacitor charge
etc.) That's the difference between theory and practice.

Digital clipping is to the best of my knowledge just that, it is with
analog clipping that bets are off.

In practice rather than theory, yes.

Trevor.

[Peter Larsen[_3_]]

Trevor wrote:

something else that was marginal ex works was overlooked in the
repair. Never a problem with left channel, including clipping as
gently as clipping should be.

Well it's not really "clipping" by definition if it's gentle. But
that seems to be the major problem, everyone has their own
definition.

Thank you for your comments Trever. We are talking about two channels of an
amplifier driven into enough overload for the clipping indicator to come on
clearly, not just flashing. Nothing audible from the left channel on that
below 650 Hz overload, but a high SMACK audible from the right channel.
Which explained why I had to get a Coral H100 repaired back when using that
amplifier on a system with passive cross-over.

Trevor

Kind regards

Peter Larsen

[Ralph Barone[_2_]]

"Peter Larsen" wrote:
Trevor wrote:

something else that was marginal ex works was overlooked in the
repair. Never a problem with left channel, including clipping as
gently as clipping should be.

Well it's not really "clipping" by definition if it's gentle. But
that seems to be the major problem, everyone has their own
definition.

Thank you for your comments Trever. We are talking about two channels of an
amplifier driven into enough overload for the clipping indicator to come on
clearly, not just flashing. Nothing audible from the left channel on that
below 650 Hz overload, but a high SMACK audible from the right channel.
Which explained why I had to get a Coral H100 repaired back when using that
amplifier on a system with passive cross-over.

Trevor

Kind regards

Peter Larsen

I briefly owned a Sansui integrated amp that had an obvious design flaw.
Whenever the output stage was driven into clipping, the output would
temporarily latch at the power rail (integrator wind-up I suppose),
resulting in a huge BANG! as the woofer cones went sailing out, only to
come to an abrupt stop when they ran out of surround excursion. That amp
was very quickly traded for an NAD that did not exhibit that behaviour.

[Trevor]

"Peter Larsen" wrote in message
k...
something else that was marginal ex works was overlooked in the
repair. Never a problem with left channel, including clipping as
gently as clipping should be.

Well it's not really "clipping" by definition if it's gentle. But
that seems to be the major problem, everyone has their own
definition.

Thank you for your comments Trever. We are talking about two channels of
an amplifier driven into enough overload for the clipping indicator to
come on clearly, not just flashing.

Right, simply where the designer chose to place the clipping indicator
threshold, not the *actual* clipping point at that instant in time.
Two different things.
Seems much of the argument here is similarly talking about two different
things.

Trevor.

[Scott Dorsey]

Mxsmanic wrote:
Scott Dorsey writes:

_all_ clipping is to some extent shaped like a square wave. As soon as you
get even a little bit of clipping, you start getting huge amounts of odd
harmonics popping up, just like a square wave.

Cool, at least I'm on the right track. So how come clipping often sounds
subjectively so much worse than a square wave?

Does it? I think of square waves as sounding pretty awful. Buzzy and
nasty.

Does the actual waveform after
conversion to digital look a lot messier than a square wave because of
problems with the conversion, or does the conversion back to analog handle the
square wave at 0 dB poorly when it's converted back to an analog waveform, or
what? Or is it just an auditory illusion even though it really is a square
wave when it comes back out?

If the system is good it looks just like a square wave. If it's not it
might have some overshoot.
--scott



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

[Mxsmanic]

Scott Dorsey writes:

Does it? I think of square waves as sounding pretty awful. Buzzy and
nasty.

Well, some of the clipping I've heard sounded like white noise rather than a
square wave, but perhaps they are not so very different. I don't care much for
either type of sound.

If the system is good it looks just like a square wave. If it's not it
might have some overshoot.

Maybe that might make it sound worse. I dunno ... I just know that I'm
supposed to keep everything below 0 dB. If the little light flashes red,
that's bad.

[Mark]

In terms of applause clipping (assuming the occasional Herculian clap that clips),
these clips are truly inaudible, especially if the mix level has been dropped and
the clip(s) do(es) not propogate further. So, no worries, IMO.


yes, that was my point exactly , thank you..

hand editing the loud claps out also works well but my point was that
the hand editing is not needed because the occasional brief clip is
not audible...

and the other part of my point was that clipping (or editing) is
preferable to some limiter or compressor pumping away on each clap.



Mark

[Arny Krueger[_4_]]

"Mark" wrote in message
...


In terms of applause clipping (assuming the occasional Herculian clap
that clips),
these clips are truly inaudible, especially if the mix level has been
dropped and
the clip(s) do(es) not propogate further. So, no worries, IMO.


yes, that was my point exactly , thank you..

hand editing the loud claps out also works well but my point was that
the hand editing is not needed because the occasional brief clip is
not audible...

True, and also claps are pretty tolerant of clipping.

and the other part of my point was that clipping (or editing) is
preferable to some limiter or compressor pumping away on each clap.

Also a good point.

[Peter Larsen[_3_]]

Mark wrote:

In terms of applause clipping (assuming the occasional Herculian
clap that clips), these clips are truly inaudible, especially if the
mix level has been dropped and the clip(s) do(es) not propogate
further. So, no worries, IMO.

yes, that was my point exactly , thank you..

hand editing the loud claps out also works well but my point was that
the hand editing is not needed because the occasional brief clip is
not audible...

and the other part of my point was that clipping (or editing) is
preferable to some limiter or compressor pumping away on each clap.

You do not appear to have tried a good fix single click functionality. Go
try it and THEN if you don't like say so. It plain and simply the best
option and the least audible one.

Mark

Kind regards

Peter Larsen

[Arkansan Raider]

wrote:

rotfl YEah know the feeling. Singers playing with their
microphones can be frustrating too.

Not if you shoot them. *ugh*

There's no excuse for that.

I still recall working
with a guy in the studio whose version of fidget was playing
with his pocket change.


Nor THAT. Not observing noise discipline is a woodshed offense in the
military on patrol AND in the studio, in MY book.

---Jeff






Richard webb,

replace anything before at with elspider

[Anahata]

On Sun, 22 Jan 2012 21:49:58 +0100, Mxsmanic wrote:

So how come clipping often sounds
subjectively so much worse than a square wave?

If you mean clipping in the digital domain sounding worse than clean
analog clipping, it's because of aliasing. Analog clipping of a simple
tone produces harmonics that are multiples of the fundamental frequency,
just like the real harmonics of a musical instrument. In the digital
domain (strictly speaking in any time-sampled domain) any of those
harmonics near the sampling rate also produce beat frequencies (aliases)
that are harmonically unrelated and could be anywhere in the audible
spectrum, or to put it in simple terms, a nasty noise.

To some extent this applies to any non-linear distortion in the digital
domain, and is the reason why some high quality digital compressors use
oversampling to get the sampling rate above harmonics at any significant
level.

It's also the reason why an A-D converter should do analog clipping
before the antialiasing filter, so the clipping harmonics above Fs/2 can
be removed.

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

[[email protected]]

JEff writes:
rotfl YEah know the feeling. Singers playing with their
microphones can be frustrating too.
Not if you shoot them. *ugh*
There's no excuse for that.

YEah I know, I almost dread it when I see a chick singer
with a handheld microphone.

I still recall working
with a guy in the studio whose version of fidget was playing
with his pocket change.

Nor THAT. Not observing noise discipline is a woodshed offense in
the military on patrol AND in the studio, in MY book.

INdeed it is. All through hsi band's album project, after
the first couple vocal overdub sessions I"d always remind
him don't play with the stuff in your pockets dude." It got
to the point where I took a little plastic tray and made him
dump the contents of his pockets in itbefore going in to
take one so that he could play pocket pool all day and not
make any noise.





Richard webb,

replace anything before at with elspider

[Arkansan Raider]

RIchard wrote:

INdeed it is. All through hsi band's album project, after
the first couple vocal overdub sessions I"d always remind
him don't play with the stuff in your pockets dude." It got
to the point where I took a little plastic tray and made him
dump the contents of his pockets in itbefore going in to
take one so that he could play pocket pool all day and not
make any noise.


Oh definitely. I do that to *myself* because I'm so paranoid about
causing the slightest little noise. It's partly why I find it so
inexcusable in others. Kind of like bringing your cell phone in...

---Jeff

[[email protected]]

JEff writes:
INdeed it is. All through this band's album project, after
the first couple vocal overdub sessions I'd always remind
him don't play with the stuff in your pockets dude." It got
to the point where I took a little plastic tray and made him
dump the contents of his pockets in it before going in to
take one so that he could play pocket pool all day and not
make any noise.
Oh definitely. I do that to *myself* because I'm so paranoid about
causing the slightest little noise. It's partly why I find it so
inexcusable in others. Kind of like bringing your cell phone in...

rotfl Have had that aggravation as well. I"m very
conscious of it, especially when I was doing more vo work
with myself as both engineer and talent. I was so conscious
of it that I threw out a very comfortable office chair I
liked to use because when doing vo sessions my slightest
movement would set up a racket in that chair, squeaks pops
and other noises that under normal circumstances were
unnoticed, but with an open mic they became intolerable.

IT's one reason why for on air ham radio work controlling
nets I've got a mic boom mounted on a straight pipe coming
from a flange mounted in my desk top, and use a foot switch
for keying. I can work the mic fairly close and know
exactly where i am in relation to it, etc.





Richard webb,

replace anything before at with elspider

[Don Pearce[_3_]]

On Mon, 23 Jan 2012 16:15:08 -0600, Arkansan Raider
wrote:

RIchard wrote:

INdeed it is. All through hsi band's album project, after
the first couple vocal overdub sessions I"d always remind
him don't play with the stuff in your pockets dude." It got
to the point where I took a little plastic tray and made him
dump the contents of his pockets in itbefore going in to
take one so that he could play pocket pool all day and not
make any noise.


Oh definitely. I do that to *myself* because I'm so paranoid about
causing the slightest little noise. It's partly why I find it so
inexcusable in others. Kind of like bringing your cell phone in...


For advice on handling mobile phones in the audience, watch this.

http://www.bbc.co.uk/news/entertainment-arts-16688007

Brilliant.

d

[Arkansan Raider]

Don Pearce wrote:


For advice on handling mobile phones in the audience, watch this.

http://www.bbc.co.uk/news/entertainment-arts-16688007

Brilliant.

d

Oh, I saw that a few days ago. Laughed my left buttock off.

Yeah, you're right: brilliant. I'm glad he had a sense of humor about it.

---Jeff

[Ty Ford]

On Tue, 24 Jan 2012 01:30:56 -0500, Don Pearce wrote
(in article ):

For advice on handling mobile phones in the audience, watch this.

http://www.bbc.co.uk/news/entertainment-arts-16688007

Brilliant.

d

Don,

Thanks for the laugh!

Wonderful.

Regards,

Ty Ford

--Audio Equipment Reviews Audio Production Services
Acting and Voiceover Demos http://www.tyford.com
Guitar player?:http://www.youtube.com/watch?v=yWaPRHMGhGA