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"TT" wrote in message
. au...


It is not just the CD but the SACD. When you have a digitally remastered
and produced album and then make the LP sound better there is a problem
here somewhere and it is not a format one ;-)

Well, the problem is not in the format either. It is a simple task,
as Davids points out, to make a digital copy of a vinyl pressing from
which it is indistinguishable. Many of us here have done that.

The problems start in post production and trying to meet the
demands of what the marketing people think the public want.

BTW Iain have you had the chance to discuss this with any of your peers in
the industry? I would be very interested on what their opinions are.

I have mentioned it to a couple of people in passing. No-one
seemed surprised. One mentioned "horses for courses" implying
that the quality requirements for an expensive limited edition vinyl
pressing and a CD which most people listen to with earbuds,
were different.:(((

This is the first time that I have come across a CD even bordering
on the the jazz category which has been subjected to this kind of
processing. Although it is not extreme, having heard the vinyl the
CD is not so pleasing.


Iain

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On Tue, 24 Mar 2009 16:31:44 +0200, "Iain Churches"
wrote:


"Dave Plowman (News)" wrote in message
...
In article ,
TT wrote:
Have you noticed once you have removed the clicks and pops
(I do it physically by cutting them out) and then convert
them to high bitrate MP3 it then removes all the surface
noise? It really is marvellous way to clean up an LP.

Any time I've had a chance to compare original to a surface noise reduced
copy I prefer the original.

Cedar makes a very good job of this. A client has compared it
to Windolene:-)

People ofte get the impression that the HF has been reduced when
the surface noise is taken away. There are many early recordings
too in which you can subsequently hear instruments you didn't
know where the-)


The brain is actually very good at reconstructing missing transients
out of broadband noise. When you de-hiss a limited bandwidth record it
can often lack what appeared to be original sparkle.

d

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In article , David Looser
wrote:
"Don Pearce" wrote in message
news:49c99e44.236997750@localhost...

I would have thought that reducing the level to zero would produce
almost as bad a click as letting it hit peak level.

No, not at all. That would only apply if the silent portion started
abruptly in the middle of a high-amplitude bit of the waveform, and as
I said I choose zero-crossings to start an end the silent portion. Do
you remember Garrad's "Music Recovery Module"? it was an analogue
real-time click remover. It also reduced the signal amplitude to zero
for the duration of the click because that was the technique that the
designer found most effective.

My memory may be at fault here as the Garrard MRM was sooo long ago. But I
though they used a bucket brigade delay line and substituted that during
the click. Must see if I can find my old reviews and check...

Slainte,

Jim

--
Change 'noise' to 'jcgl' if you wish to email me.
Electronics http://www.st-and.ac.uk/~www_pa/Scot...o/electron.htm
Armstrong Audio http://www.audiomisc.co.uk/Armstrong/armstrong.html
Audio Misc http://www.audiomisc.co.uk/index.html

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On Tue, 24 Mar 2009 09:16:59 +0000 (GMT), Jim Lesurf
wrote:

But I'd be interested to hear what others may think of using perception
based reduction like MP3 encoding with the explicit aim of suppressing
background noise.

I think there is an inherent problem with this. If the background
noise is low enough that you can't hear it, making an MP3 to suppress
it is unnecessary.

On the other hand, if it is loud enough to hear, the MP3 coder will do
its level best to keep it audible and unchanged. That will steal
valuable bits that should be used for keeping up the fidelity of the
music.

If the coder does have an effect on the noise, it is never to suppress
it, but simply to do a poor job of reproducing it, turning it from an
innocuous hiss to an unpleasant swirling sound effect.

d

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In article , Arny
Krueger
wrote:
"David Pitt" wrote in message

Jim Lesurf wrote:


The difficulty is that the channel behaviour in such a case is
limited by distortion in quite a complex manner, so determining the
practical value is difficult.

Expanding on that a bit...

Vinyl is inherently distorted at high frequencies and high amplitudes.
There is inherent geomtric distortion due to the difference between the
shape of the cutting stylus and the playback stylus. There is
additional deformation of the groove wall due to high inertial forces.
The playback device itself has trackability problems which generally
increase with decreasing price. We're not talking about 0.01%
distoriton, the nonlinear distortion is up in the 3-10% or higher
range. The harmonics that are created by the nonlinearity are usually
in the ultrasonic range, but the IM products splatter all over the
audio band.

To make things worse, when considered as a stereo pair the 'crosstalk' also
injects distortion from one channel to the other with L only / R only /
Mono only / Diff only all being 'special cases' in various senses. Hard to
know how to assess the meaning of this for stereo listening where the
sounds for the two channels have varying degrees of correlation.

Contrast this with CD's linear PCM which is inherently distortion free
at all levels right up to 0.001 dB below clipping.



A (plausible?) attempt at an answer to this is at :-

http://www.hydrogenaudio.org/forums/...hp/t35530.html

This does ignore any affects of distortion.

It understates the fact that tracing distortion inherent in the LP
format is a big issue when you go much above 5-8 Khz with good quality
playback equipment. The performance of mainstream vinyl players in the
days of was well short of that.

Particularly when you avoid special cases like mono or single channel only.

Not yet looked at the above page. Must have a look, but from your comments
I suspect they have gilded over the difficulties in assessment. If so,
though, I find that understandable given the potential complexity and the
task of choosing genuinely relevant assumptions, etc. :-)

Slainte,

Jim

--
Change 'noise' to 'jcgl' if you wish to email me.
Electronics http://www.st-and.ac.uk/~www_pa/Scot...o/electron.htm
Armstrong Audio http://www.audiomisc.co.uk/Armstrong/armstrong.html
Audio Misc http://www.audiomisc.co.uk/index.html

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"TT" wrote in message
. au...

"David Looser" wrote in message
...
"TT" wrote in message
. au...



In Cool Edit Pro when I have a particularly bad click/pop I expand the
wave form out as far as I can an just cut the offending piece of noise.
Since we are talking about a very small period of time I have never
noticed any discontinuity to the resulting wave file.

The discontinuity can create a click, and the whole object of the exercise
is to get rid of them!

Hearing a missing 0.005sec-0.01sec piece of music missing is a bit of an
ask ;-)

That's 5-10 msec, I would nomally expect to remove a far shorter piece of
the recording than that, often below 1 msec. Above 3 msec the effect is
definitely audible.

I find using any program that does this automatically just destroys the
music so I therefore do it manually.

If you are talking about 78s then I'd agree with you. But if you are working
from reasonably clean vinyl then you've got the settings wrong.

One problem with manual removal is finding the clicks in the first place.
High-amplitude clicks are no problem, but low-level ones,when the click
amplitude is lower than that of the programme material around it, can be the
devil's own job to find. But the software can often still zap them.

If you are happy restricting yourself to just one technique fine, but I use
around half-a dozen different techniques, as there is no one that is "best"
in all circumstances.

David.

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"Arny Krueger" wrote in message
...

IME a far better approach with CEP/Audition is to apply an appropriate low
pass filter over the area that was afflicted with the tic, which is
usually a few milliseconds or less. I use corner frequencies on the order
of a few 100 Hz in severe cases, to several kHz in mild cases. This avoids
the zero-crossing issue.

That just turns a "click" into a "thump". It may make be less aurally
intrusive, but it doesn't get rid of
it.

Actually I often use a *high-pass* filter over a high-energy click area
before removing the
click, that removes the DC shift that a high-amplitude click creates and
means that I need silence a far shorter period.

David.

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"David Looser" wrote in
message
"Arny Krueger" wrote in message
...

IME a far better approach with CEP/Audition is to apply
an appropriate low pass filter over the area that was
afflicted with the tic, which is usually a few
milliseconds or less. I use corner frequencies on the
order of a few 100 Hz in severe cases, to several kHz in
mild cases. This avoids the zero-crossing issue.

That just turns a "click" into a "thump". It may make be
less aurally intrusive, but it doesn't get rid of it.

You should play around with the idea before you comment.

Part of the art is getting the corner frequency low enough that you don't
get a thump.

More to the point, there may be a brief period over which the highs are
attenuated, but that is pretty easy to miss.

Actually I often use a *high-pass* filter over a
high-energy click area before removing the
click, that removes the DC shift that a high-amplitude
click creates and means that I need silence a far shorter
period.

DC shift? Never see any in my transcriptions.

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"Jim Lesurf" wrote in message
...
In article , David Looser
wrote:
"Don Pearce" wrote in message
news:49c99e44.236997750@localhost...

I would have thought that reducing the level to zero would produce
almost as bad a click as letting it hit peak level.

No, not at all. That would only apply if the silent portion started
abruptly in the middle of a high-amplitude bit of the waveform, and as
I said I choose zero-crossings to start an end the silent portion. Do
you remember Garrad's "Music Recovery Module"? it was an analogue
real-time click remover. It also reduced the signal amplitude to zero
for the duration of the click because that was the technique that the
designer found most effective.

My memory may be at fault here as the Garrard MRM was sooo long ago. But I
though they used a bucket brigade delay line and substituted that during
the click. Must see if I can find my old reviews and check...

Slainte,

Jim

--
Change 'noise' to 'jcgl' if you wish to email me.
Electronics
http://www.st-and.ac.uk/~www_pa/Scot...o/electron.htm
Armstrong Audio http://www.audiomisc.co.uk/Armstrong/armstrong.html
Audio Misc http://www.audiomisc.co.uk/index.html

That was also my recollection. A bucket-brigade delay line stored the audio
which was dropped in to cover the click.

S.
--
http://audiopages.googlepages.com

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"Serge Auckland" wrote in message
...


That was also my recollection. A bucket-brigade delay line stored the
audio which was dropped in to cover the click.


Then you are both wrong. They did consider doing that, but rejected it in
favour of attenuating the signal during the click as it was audibly
superior. There is still a bucket-brigade delay line, but that is to
compensate for the delay in the click-detector. The attenuation is performed
by LDRs.

David.