Clipped waves and distortion.

[concretecowboy71]

Hey guys.

I was wondering how many people might have insight into the issue of loud/clipped wave forms and its relation to audio quality on disc.

I do know that clipping in all forms causes and is related to distortion, but how does a machine like a lathe and all of its components react to it?

It seems like the few sound quality issues I have had with cuts have been related to masters that have been heavily limited and in one case, clipped into square wave tops.

Should I request new masters in these situation?

Thanks

[blacknwhite]

At one time, I had an audio-processing plugin which you could "press a button", and it would automatically look for clipped waves at the peak level, and round them slightly (user-controllable).

It required that there would have been NO subsequent EQ changing on the audio, between when the clipping occurred and when this process was run.

It would only smooth out "jaggies" (square edges) at the loudest peak levels, not anywhere else.

Sorry, I can't remember the name of the function.

Seems it should be a standard function available in most digital domains, but I don't know.... anyone else?...

- Bob

[cymbalism]

From my personal experience in both releasing music and cutting, over compressed and limited files cause nothing but a muddy disastrous cut. Perfect examples of this are the vinyl pressings of metallica's death magnetic and my chemical romances's three cheers for sweet revenge. Unlistenable records and not worth a penny.

Best bet, don't cut anything that doesn't have peaks and if you have to, expect a subpar record out of the deal.

The music industry needs to go back to AAD CDs and master lps correctly instead of fucking all us real music lovers over by delivering half assed listening material.

[concretecowboy71]

Thanks for the input from both the cutter and artistic side.

The one issue I am dealing with now is a master that has many squared off wave forms. I have a screen shot with 6 in the matter of one second.

The master they supplied was from the production CD, so it is also 16 bit / 44.1k. The cut sounds like the CD, but my opinion was that the CD did not sound very good to start with.

I also understand that when these machine were designed and built, nobody was mastering like this.

Thanks again.

[cymbalism]

I recut the my chemical romance three cheers album for myself from the cd because the pressed version sounded so horrible and it came out way better than the released version but still suffers from overcompression.

Once that master has been pushed to the limit you pretty much just have to eq the shit out of it in order to somehow make it translatable to grooves, sometimes it works but it's still not perfect.

What are you cutting if you don't mind me asking?

[concretecowboy71]

It is a classic rock thing along the lines of The Band or Leon Russell.

I will leave artist names out for obvious reasons.

The master is stepped on really hard and peaks out at 0dbfs on my workstation.

I would think that you would want much more dynamics with this kind of music.

[markrob]

Hi,

I don't think threr should be any problem cutting a heavily clipped source as long as you don't try to cut too hot. As an example, here is a short snippet of a Joe Jackson tune. I often use this track as a reference. This source material has little or no limiting (very high crest factor). I loaded this into Audition and set up a hard clipping effect with the peaks chopped about 10db from peak. If you load this into a wav editor you can see what I've done. You can clearly see the peaks lopped off. This is flat top clipping unlike some of the better brick wall limiters that have a softer approach. If you listen to the file, you won't hear much change in sound level or quality at the transition. I didn't try to cut this, but as long as you setup you cutting chain such that the first part of the file cuts fine, the second part should present no problem.

http://home.comcast.net/~markrob1066/docs/Jackson_Clipped.wav


The problem would be if you tried to cut this 10db hotter than the original track. I'm sure this is not as severe as some of the crap that goes on in the ongoing loudness wars.

Mark

[concretecowboy71]

That was very interesting to look at and listen to.

I think the issue with the source I am dealing with is that not only is it clipped, it is very hot also. I would have no problem cutting the track you posted and like you said you can hear little difference in the sources (snare loses some of its zing).

I don't know how the clipping came about; improper mixing, intentional or weird pre-mastering.

Thanks for the insight, very educational.

[cymbalism]

Is there any other media it was available on? Like reel or tape or is this a newer artist which only had the cd issue of their release

[Aussie0zborn]

I also understand that when these machine were designed and built, nobody was mastering like this.

Quite true. What you are talking about is not what we used to call mastering.

Good luck with it. You might send those screen shots to your client together with the test pressings and a little note that says something polite but puts the responsibility onto them.

[dietrich10]

I always ask for 'vinyl' masters when receiving these files from labels or artists. I am sure you are already bringing the levels down -10db just to cut?

Explain that to the label or even ask for the # of their mastering engineer.
If this is the only master the only way around it is to cut even quieter than if files not limited to death.

One job I did had 'vinyl' masters supplied by one of the biggest guys at Sterling...which were of course also the CD masters....
Not easiest call I ever made requesting new masters but he did and it saved the record.

@clint. ask vince about the Stars 7" first cuts compared to 2nd
D

[concretecowboy71]

I did send a screen shot. Thanks for suggesting that. I just wanted them to get an idea of what was going on with their audio.

This is a new artist and they provided no other media for me to cut from.

I have requested new masters if they want a re-cut.

I felt it was a really nice cut and sounded great given what I was asked to work with.

[subkontrabob]

hard clipping creates additional harmonics = high frequency content

[markrob]

hard clipping creates additional harmonics = high frequency content

Hi,

That's the common wisdom on the subject. Based on clipping a sine wave into something approaching a square wave, you do see increased harmonics. But it gets muddy when you start to look at more complex cases. You can show high frequency content decreasing with clipping. Here is a case I found on a quick search.

http://www.st-andrews.ac.uk/~www_pa/Scots_Guide/audio/clipping/page3.html

Mark

[dietrich10]

here is similar issue I am having. turned down 10db to make -2 peak cut.
still sounds pushed

[markrob]

here is similar issue I am having. turned down 10db to make -2 peak cut.
still sounds pushed

[/img]http://www.complete-usa.com/cut.jpg

Hi,

That looks nasty. But pretty typical of what you see these days. How bad does the actual file sound? 10 db might not be enough. It would be interesting to loop a portion of the file and cut starting at very low level (-20??) and raise the level in 2 or 3db steps each loop. Can it be cut at any any level that gives reasonable sounding results? If you can find such a level, when you playback the cut and compare with a more sane source, is the subjective loudness in the same ballpark?

Mark

[mossboss]

Hey All
Yes one can polish a turd but it is still a turd however shiny
There is no way you can cut this expecting to get any more than reasonable results
On a subjective or comparative listening test say a/b of the submitted work with what has been cut of course there would be a significant difference and it will sound better after such a harsh treatment but is this what its all about
What is wrong in getting the mastering guy to do it correctly or at least provide one with some head room or ceiling
This is not that hard to do Or are we to scared offending someone by even suggesting that it is not up to scratch
These band aid measures do not do the game any good IMHO
Cheers

[dietrich10]

here is similar issue I am having. turned down 10db to make -2 peak cut.
still sounds pushed

[/img]http://www.complete-usa.com/cut.jpg

Hi,

That looks nasty. But pretty typical of what you see these days. How bad does the actual file sound? 10 db might not be enough. It would be interesting to loop a portion of the file and cut starting at very low level (-20??) and raise the level in 2 or 3db steps each loop. Can it be cut at any any level that gives reasonable sounding results? If you can find such a level, when you playback the cut and compare with a more sane source, is the subjective loudness in the same ballpark?

Mark

I can cut to translate 95% to the file providing. cutting lower than the -2db peaks doesnt change the quality or the dynamics.

[Angus McCarthy]

Hey All
Yes one can polish a turd but it is still a turd however shiny
There is no way you can cut this expecting to get any more than reasonable results
On a subjective or comparative listening test say a/b of the submitted work with what has been cut of course there would be a significant difference and it will sound better after such a harsh treatment but is this what its all about
What is wrong in getting the mastering guy to do it correctly or at least provide one with some head room or ceiling
This is not that hard to do Or are we to scared offending someone by even suggesting that it is not up to scratch
These band aid measures do not do the game any good IMHO
Cheers

I have to agree. The only way to defeat the sickness that is the Loudness War is to confront the source.

Frustratingly it is often the producer or the band itself that insists on having their music brick-walled. Most mastering engineers know better and would put out high-dynamic masters if the clients allowed them to.

[mossboss]

Thanks for that Angus
That was my point some are to scared to tell them this is CRAP man go away
It can be done subtly or blatantly however if people out there put the $$$ first what is the point We just end up with more bad music that it does not sell and that is the point Music has to be attractive to the buyer if anyone is to get any kudos out of it
Cheers