Am I clipping?

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Scotsman

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I use Adobe Audition 1.0 a lot for recording guitar and vocals, and figured it's time I learned how to discern whether my recordings are clipping and, if so, how to fix them.

I'm working on another song that I've just recorded and have taken a screenshot to show the wave file.

Link to Screenshot

My question is:

Where the wave goes outside the white lines on each channel, does that indicate clipping? I've set the scale to decibels as that's the easiest measurement for me to understand at the moment. There are a few instances where the peaks extend beyond the white-line envelope.

If this does indicate clipping, is it simply a matter of reducing the amplification (Effects > Amplitude > Amplify... - cut by xdb)? Or would I use another feature under the Effects > Amplitude menu (Hard limiting, Normalize, Envelope, etc.)?

Help!
 
The white lines indicate the -1dB point (you can set them elsewhere - it's somewhere in the options). Watch the meters - if they go red, it's clipped. Without zooming in a lot, you won't be able to tell from the waveform if transient peaks go over or not. The "analyse statistics" tool would tell you the full statistical story.

When you record, use the windows mixer to ensure the meters never go into the red - ever. Or control your input externally (such as with an external mixer).

All the tools such as hard limiting, compression, and normalising, operate on the already-recorded waveform. You can use the first two of these (if correctly set up) to make your audio sound louder while still not allowing it to clip. Normalising is usually used to raise the whole level enough so that the very loudest peak doesn't quite go into the red (by 0.01dB if you want).
 
Thanks! As for the peaks that go off the screen, can I work on just those by decreasing the amplitude by, say, cutting by 1db and seeing whether that brings it down into the 'safe' zone?
 
You can but it's better to reduce the master volume in the multitrack stage before mixdown. Then after mixdown normalize or hard limit to bring the whole track level to a more uniform level.

Tukkis
 
Hmm, if the peaks already exceed 0dB (full scale) then they are already clipped (unless this is a result of 32 bit float processing on 32 bit files, in which case you should be able to normalise them back to a permitted level). There's a clip restoration tool in effects > noise reduction.
 
Just to clarify a bit, going red doesn't NECESSARILY mean you've clipped - it just means that you've hit "0db,"...the test is in how it sounds. However, if you can hear that you've clipped digitally, I don't think it can be 'fixed.' The horribleness of that sound can be decreased somewhat with some tools, but once it's clipped, it doesn't matter how much you turn it down, the clipping will be there...with maybe a band-aid on it, lol

Good luck,
Chris
 
By the way...looking at that wave form, if I were you...I'd run the Hard limiter in CEP/AA with a ceiling of -.3 (notice the decimal point) and with an output of 3.5db. That'll get everything below 0db (-.3db will be as loud as it gets), but the overall volume and apparent volume of the track will go up. If there's any obnoxious clipping, you should be able to tell with your ears.
 
Thanks for the advice again folks. I've spent some more time with AA today and am beginning to understand it better. I need to watch my input levels more closely in order to avoid trying to make the proverbial silk purse.

I've uploaded the recording in question in case anyone's interested in hearing where I am on the AA learning curve. I edited the wave file by zooming in on the parts where the clip meter was going red and reducing the amplitude manually. It seemed to work but was quite a long and laborious task.

So, here's the recording. Comments would be very welcome!

Quicksand MP3

Thanks
 
"It seemed to work but was quite a long and laborious task."

LOL Welcome to mouse mixing.

I can't hear any clipping on this one. My thinking is that if you *are* clipping anywhere, it's on the guitar cuz of the sudden level spikes. Note: no need to track it so hot next time.

Comment: there's a sound or frequency in the vocal which sounds like it shouldn't be there. I noticed it because with just vocal and acoustic, everything's right out there and naked. Maybe a wonky frequency you're picking up from your room? Have you tried sweeping the 300-400 Hz range on the vocal?
 
dobro said:
"Comment: there's a sound or frequency in the vocal which sounds like it shouldn't be there. I noticed it because with just vocal and acoustic, everything's right out there and naked. Maybe a wonky frequency you're picking up from your room? Have you tried sweeping the 300-400 Hz range on the vocal?
Click to expand...

I'm not actually sure what you mean by sweeping. Could you explain please?

Thanks
Cams
 
Scotsman said:
I'm not actually sure what you mean by sweeping. Could you explain please?

Thanks
Cams
Click to expand...
By using a parametric EQ (Effects>>Filters>>Parametric EQ), make about a 4db cut around 400Hz with a "Q" of around 2 (that's the width of the EQ range effected). Then "sweep" it left and right with the slider to see how it changes the sound, hopefully for the better.
 
There's another variant of sweeping: you can sweep for the crappy frequencies. Choose a very narrow Q in the parametric EQ - maybe something like 12 - you're just going to examine a very narrow frequency range. Boost it 9 or 10 dB - this really accentuates whatever frequency you're sweeping through, and then sweep left and right through the range of frequencies you want to check - for that vocal track you posted, I'd be looking at everything between 300 Hz and 500 Hz. If a frequency is making your sound ugly, then when the parametric sweeps through it, it'll sound *really* ugly. That will be the frequency you then choose to cut. When you cut it, use a much broader Q - maybe 1.0, and cut only a little - maybe 2 or 3 dB. It should sweeten the sound, but you're still gonna hafta listen to how the track sounds when it's back in the mix.
 
Thanks again for the replies Dobro and Chris. I just looked at the Parametric EQ settings and am afraid I'm not quite sure how to do what you've suggested. Could someone please hold my hand and walk me through the procedure? I'm be most grateful.

Thanks
 
Mr Scotsman, in Multitrack View click on "EQ" beside "Vol" in the track you want to work with. Right click in the center of the panel that says "H-M-L" (little vertical windows) and a simple parametric EQ control window will appear. There will be 3 handles on a horizontal line that represent boost and cut (push up for boost, down for cut). The Q is set by sliders directly below. Play a track back and play with these and that will give you a feel for how a parametric works. Once you are comfortable with it go to the parametric in Effects/Filters/Parametric Equalizer in Edit View and you'll find a more elaborate version. Note: to activate a band, click on the check box to its left. I actually prefer the one in Multitrack View because it's important for your EQ to fit in well with the rest of the song and you can't hear the other tracks when you are using Edit View.

Hope this helps.
 
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