Editing Audio

i'm cutting up Audio in Cubase but I'm getting harsh clipping sounds and the start of the cuts? is there a way round this? a De-esser or something?

thanks

test.mp3 69.29 kB · 1 download

  On 8/12/2009 at 2:31 PM, G. I. Raffe said:

i'm cutting up Audio in Cubase but I'm getting harsh clipping sounds and the start of the cuts? is there a way round this? a De-esser or something?

 

thanks

 

test.mp3 69.29 kB · 1 download

It's called a DC offset - where the waveform begins from a non zero position. 2 ways to get around it:

1. Make sure you cut all your audio where the waveform passes through zero

or

2. Apply a very short fade in (1ms) to the beginning of all your cuts. Not sure how to do this in cubase, dead easy in logic though.

great thanks a lot. I'll put a fade on the clips

Is there a plug-in for doing this ?

i don't use cubase but i imagine it has both a "snap to 0 crossing" option, and most likely has presets for fade-in / out

  On 8/12/2009 at 2:59 PM, G. I. Raffe said:

great thanks a lot. I'll put a fade on the clips

 

Is there a plug-in for doing this ?

There are loads and loads of fade options in Cubase, the audio file will have a fade handle in the top left, there's a 'quick fade' option which is probably appropriate here, and you can set a preference for always making cuts at a 0 crossing point if you're doing the intial editing in Cubase.

Cheers kakapo

  On 8/12/2009 at 2:47 PM, esquimaw said:

  On 8/12/2009 at 2:31 PM, G. I. Raffe said:

i'm cutting up Audio in Cubase but I'm getting harsh clipping sounds and the start of the cuts? is there a way round this? a De-esser or something?

 

thanks

 

test.mp3Fetching info...

 

It's called a DC offset - where the waveform begins from a non zero position. 2 ways to get around it:

 

1. Make sure you cut all your audio where the waveform passes through zero

or

2. Apply a very short fade in (1ms) to the beginning of all your cuts. Not sure how to do this in cubase, dead easy in logic though.

I don't think that is called DC offset, unless he is applying cuts where there should be silence. If that is the case, use a DC offset corrector, or apply a highpass filter @ 20Hz, and the offset will go away(just put one on there anyways just in case, no harm to audio). But it is normal for there to be clicks if you are cutting active audio, create a short fade in (and a fade-out).

  On 8/12/2009 at 11:14 PM, Bubba69 said:

  On 8/12/2009 at 2:47 PM, esquimaw said:

  On 8/12/2009 at 2:31 PM, G. I. Raffe said:

i'm cutting up Audio in Cubase but I'm getting harsh clipping sounds and the start of the cuts? is there a way round this? a De-esser or something?

 

thanks

 

test.mp3Fetching info...

 

It's called a DC offset - where the waveform begins from a non zero position. 2 ways to get around it:

 

1. Make sure you cut all your audio where the waveform passes through zero

or

2. Apply a very short fade in (1ms) to the beginning of all your cuts. Not sure how to do this in cubase, dead easy in logic though.

 

I don't think that is called DC offset, unless he is applying cuts where there should be silence. If that is the case, use a DC offset corrector, or apply a highpass filter @ 20Hz, and the offset will go away(just put one on there anyways just in case, no harm to audio). But it is normal for there to be clicks if you are cutting active audio, create a short fade in (and a fade-out).

Yeah, a DC offset is where the bias of an entire waveform is skewed to the positive or negative, ie where the waveform should be at 0 it is actually at +0.200 or whatever.

fades are the key, and they are such a fundamental tool in digital audio that all the major programs have fade's built in. I like cubases, just select all the offending audio and grb the little blue triangles in the top corner of one of the waveforms, sorted!

  On 8/13/2009 at 1:21 AM, welcome to the machine said:

  On 8/12/2009 at 11:14 PM, Bubba69 said:

  On 8/12/2009 at 2:47 PM, esquimaw said:

  On 8/12/2009 at 2:31 PM, G. I. Raffe said:

i'm cutting up Audio in Cubase but I'm getting harsh clipping sounds and the start of the cuts? is there a way round this? a De-esser or something?

 

thanks

 

test.mp3Fetching info...

 

It's called a DC offset - where the waveform begins from a non zero position. 2 ways to get around it:

 

1. Make sure you cut all your audio where the waveform passes through zero

or

2. Apply a very short fade in (1ms) to the beginning of all your cuts. Not sure how to do this in cubase, dead easy in logic though.

 

I don't think that is called DC offset, unless he is applying cuts where there should be silence. If that is the case, use a DC offset corrector, or apply a highpass filter @ 20Hz, and the offset will go away(just put one on there anyways just in case, no harm to audio). But it is normal for there to be clicks if you are cutting active audio, create a short fade in (and a fade-out).

 

 

Yeah, a DC offset is where the bias of an entire waveform is skewed to the positive or negative, ie where the waveform should be at 0 it is actually at +0.200 or whatever.

 

fades are the key, and they are such a fundamental tool in digital audio that all the major programs have fade's built in. I like cubases, just select all the offending audio and grb the little blue triangles in the top corner of one of the waveforms, sorted!

Um, no. A DC offset is where a waveform begins from non zero. You are talking about an incorrect DC Bias, where the mean amplitude of the wave is non-zero.

As for getting rid of the clicking sound, a highpass filter will help, but will not completely solve the problem. Cut your audio at zero crossings, or use a fade to force the amplitude to begin from zero. Hey presto, clicks are gone. I don't mean to be argumentative, but in this case you are wrong. In audio circles a DC offset is how I have described. They can be used creatively too - but be careful, the gain makeup of them is pretty abnormal and can rupture speaker cones and eardrums at sufficient volumes.

Hmm, I have always thought that DC offset and DC bias were synonymous, both meaning "the mean amplitude of the waveform". I'd be interested to see who decided for it to mean "a waveform beginning from non-zero" because that is an entirely new definition for me, and most likely wrong one, only to become widespread "knowledge" in audio circles from gross misuse. That definition sounds more like what I call "phase offset", or some hybrid of the two, because both the terms "DC offset" and "phase offset" can cause the non-zero value. DC-offset is a y-axis offset measurement, phase offset is an x-axis measurement.

For example, a sine wave with a "DC offset" of zero and a "phase offset" of zero should be perfect. Starting at zero and having a mean amplitude of zero. If the sine wave doesn't start at zero, it could be because of a non-zero value for either of those measurements. If it is only "DC offset" that was causing a non-zero start, then that would mean the problem could be entirely cured by applying, according to wikipedia, a "one-pole one-zero high-pass filter."

  On 8/13/2009 at 2:46 AM, Bubba69 said:

Hmm, I have always thought that DC offset and DC bias were synonymous, both meaning "the mean amplitude of the waveform". I'd be interested to see who decided for it to mean "a waveform beginning from non-zero" because that is an entirely new definition for me, and most likely wrong one, only to become widespread "knowledge" in audio circles from gross misuse. That definition sounds more like what I call "phase offset", or some hybrid of the two, because both the terms "DC offset" and "phase offset" can cause the non-zero value. DC-offset is a y-axis offset measurement, phase offset is an x-axis measurement.

 

For example, a sine wave with a "DC offset" of zero and a "phase offset" of zero should be perfect. Starting at zero and having a mean amplitude of zero. If the sine wave doesn't start at zero, it could be because of a non-zero value for either of those measurements. If it is only "DC offset" that was causing a non-zero start, then that would mean the problem could be entirely cured by applying, according to wikipedia, a "one-pole one-zero high-pass filter."

It is used to describe the audible effect of of an audio waveform that begins from non-zero. It's just the accepted usage as far as I'm aware. The language is borrowed from that of traditional electronics, but applied differently I suppose. Anyway, a phase offset would have no bearing on a sine wave's 'perfectness', unless it was being played in or out of phase with another perfect sine wave. A sine wave is the same shape whether it's left a bit or right a bit.

Also, I just checked Wikipedia's definition - I wouldn't trust that article. Cites no sources etc and is unspecific.

  On 8/13/2009 at 2:15 AM, esquimaw said:

  On 8/13/2009 at 1:21 AM, welcome to the machine said:

  On 8/12/2009 at 11:14 PM, Bubba69 said:

  On 8/12/2009 at 2:47 PM, esquimaw said:

  On 8/12/2009 at 2:31 PM, G. I. Raffe said:

i'm cutting up Audio in Cubase but I'm getting harsh clipping sounds and the start of the cuts? is there a way round this? a De-esser or something?

 

thanks

 

test.mp3Fetching info...

 

It's called a DC offset - where the waveform begins from a non zero position. 2 ways to get around it:

 

1. Make sure you cut all your audio where the waveform passes through zero

or

2. Apply a very short fade in (1ms) to the beginning of all your cuts. Not sure how to do this in cubase, dead easy in logic though.

 

I don't think that is called DC offset, unless he is applying cuts where there should be silence. If that is the case, use a DC offset corrector, or apply a highpass filter @ 20Hz, and the offset will go away(just put one on there anyways just in case, no harm to audio). But it is normal for there to be clicks if you are cutting active audio, create a short fade in (and a fade-out).

 

 

Yeah, a DC offset is where the bias of an entire waveform is skewed to the positive or negative, ie where the waveform should be at 0 it is actually at +0.200 or whatever.

 

fades are the key, and they are such a fundamental tool in digital audio that all the major programs have fade's built in. I like cubases, just select all the offending audio and grb the little blue triangles in the top corner of one of the waveforms, sorted!

 

Um, no. A DC offset is where a waveform begins from non zero. You are talking about an incorrect DC Bias, where the mean amplitude of the wave is non-zero.

 

As for getting rid of the clicking sound, a highpass filter will help, but will not completely solve the problem. Cut your audio at zero crossings, or use a fade to force the amplitude to begin from zero. Hey presto, clicks are gone. I don't mean to be argumentative, but in this case you are wrong. In audio circles a DC offset is how I have described. They can be used creatively too - but be careful, the gain makeup of them is pretty abnormal and can rupture speaker cones and eardrums at sufficient volumes.

No, sorry man that is NOT dc offset. It is the same thing as an incorrect DC bias and it is when a DC signal is added to an AC current, normally by the soundcard or other poorly designed digital device. Thats where the offset comes from, because a DC signal is a constant voltage added to the signa and its what gives the waveform its non zero bias.

An offset by definition is a system which has maintained its 'pattern' but is moved in relation to something else, a waveform that starts at a non-zero point of crossing is not an offset.

A high pass filter will not help a click caused by a non zero point of crossing, it is caused by the digital hardware being forced to go from a zero state to a positive or negative state in an infinitely small amount of time! A filter may change the nature of the click as it changes the waveform but it will not get rid of it. The reason a high pass filter will help a DC offset is that the DC current that has sneaked into the signal is normally a very low frequency and will be removed by the low pass filter. In some cases this isn't the case and a function like 'remove DC offset' from adobe audition (I'm sure they all have similar but the last time I needed to remove a DC offset I was using this program!) will do the job.

I know we are just arguing semantics, but a normal waveform is kind of AC signal, not DC. A single sample from a normal waveform with a correct DC bias cannot be considered a DC signal, it is a sample from an AC one and as such it cannot be considered a DC offset. No matter how far the first sample is from 0 there is nothing DC about it!

Also, think about when you use the 'remove DC offset' function in a program like adobe audition. It is a function that is applied to the entire waveform, but when you are adding fade to remove a click (In almost all audio programs!) you specify the length of fade you need, depending on the severity of the click thats there. You need to be able to choose different fade times. When removing a DC offset you get no options along those lines, because it has nothing to do with getting rid of non-zero point of crossing clicks, and is not a process specific to the start and end of files!

phew... sorry to go on!

no wiki was used in writing this :)

glad someone agrees with me, I thought I was going crazy.

Yikes, ok. Perhaps I am wrong, perhaps not. I'm fairly certain that I will keep calling it that though.

What on earth do you call it then? Give it a name!

  On 8/14/2009 at 1:39 AM, esquimaw said:

Yikes, ok. Perhaps I am wrong, perhaps not. I'm fairly certain that I will keep calling it that though.

 

What on earth do you call it then? Give it a name!

Dunno, I always call it a 'point of zero crossing' or 'zero crossing' when it's cut at the 'correct' place. Thats would be the techy name for it borrowed from electronics, otherwise I call it a point of non-zero crossing. Which makes sense but isn't the most elegant of phrases. Or a mid-cycle cut would work as a term.

To be honest with fades being implemented well in most programs these days it has become standard to just fade everything! It only takes a few ms to sort out any clicks so we don't tend to even mention zero crossing in the studio, we just say 'have you done your edit-fades? etc' Just cut where you want and add your fades!

Even a few ms can cause troubles when you cut drum hits right up to the transient, as it can change that initial transients attack, so I always leave a little bit of space before the hit for fades. I always do this with recorded audio (ie a mic from a drum track) because if you edit you are just nudging a drum backwards or forwards. If you want to quatize the audio I'll set an anchor point at the initial transient (where a lot of people would slice), this is easy in logic. then you can leave the initial gap of audio confident that the anchor point will be what snaps to the bar or beat. if you are doing very glitchy sliced break stuff you may need to be a bit tighter to the transient though, but you can normally leave the required 5ms for a fade at the beggining of each hit without mucking up the timing in any bad way!

I always used to think that cuts had to be made right before the transient to keep the hits in time, now I turn snap off and line up by ear and eye. It makes editing quicker and more fun, it keeps some human-ness in the music and means you get no problems with applying blanket fades as well!

  On 8/14/2009 at 2:50 AM, welcome to the machine said:

  On 8/14/2009 at 1:39 AM, esquimaw said:

Yikes, ok. Perhaps I am wrong, perhaps not. I'm fairly certain that I will keep calling it that though.

 

What on earth do you call it then? Give it a name!

 

Dunno, I always call it a 'point of zero crossing' or 'zero crossing' when it's cut at the 'correct' place. Thats would be the techy name for it borrowed from electronics, otherwise I call it a point of non-zero crossing. Which makes sense but isn't the most elegant of phrases. Or a mid-cycle cut would work as a term.

 

To be honest with fades being implemented well in most programs these days it has become standard to just fade everything! It only takes a few ms to sort out any clicks so we don't tend to even mention zero crossing in the studio, we just say 'have you done your edit-fades? etc' Just cut where you want and add your fades!

 

Even a few ms can cause troubles when you cut drum hits right up to the transient, as it can change that initial transients attack, so I always leave a little bit of space before the hit for fades. I always do this with recorded audio (ie a mic from a drum track) because if you edit you are just nudging a drum backwards or forwards. If you want to quatize the audio I'll set an anchor point at the initial transient (where a lot of people would slice), this is easy in logic. then you can leave the initial gap of audio confident that the anchor point will be what snaps to the bar or beat. if you are doing very glitchy sliced break stuff you may need to be a bit tighter to the transient though, but you can normally leave the required 5ms for a fade at the beggining of each hit without mucking up the timing in any bad way!

 

I always used to think that cuts had to be made right before the transient to keep the hits in time, now I turn snap off and line up by ear and eye. It makes editing quicker and more fun, it keeps some human-ness in the music and means you get no problems with applying blanket fades as well!

Well, in that case I dub it an Andrews' Audio Anomaly Non-zero Sample-cut Really Gash Noise (AAANzScRGN)

Signed,

Thomas Andrews BA(Hons)