when is clipping not clipping?

[dobro]

I record digitally. Everybody knows digital distortion is unforgiving and particularly ugly. Yet I've noticed something. I'll record a couple of tracks and play them back, and there's some distortion. However, if I reduce the master gain in the software, the distortion disappears (sometimes it disappears if I just reduce the level on an individual track). If I save the tracks at the reduced gain, there's no distortion.

So, am I correct in thinking the following about digital recording:

1 The best scenario is when you play it back and there's no distortion (Hurray! Save that sucker!)

2 Another scenario is when you play it back, but upon hearing distortion, you reduce either individual channel level or overall level to the point where the distortion disappears. Save that sucker, and say a minor prayer of thankfulness and learning.

3 The worst scenario is the one in which playback reveals distortion that no amount of gain reduction will remedy.

This is really important to me. I have, in the past, ditched/thrown out/deleted loads of takes because of distortion. These have been tracks which ranged from decent to good.

 

[camn]

the key is WHERE is it clipping...?

Lets talk about my setup, since its right here.

If I distort my preamp tubes... theres no getting around it.
If I distort my power tubes... theres no getting around it.
If I distort my a/d converters... theres no getting around it.
If I have distortion at the EQ stage of my channel strip...I can turn my trim down.
If I clip my soundcard inputs..I can reduce my master volume on my mixer...

---------HERE SOMETHING IMPORTANT HAPPENS----
____________Im recording HERE________
ok.. if I have a clean signal here, Im cool. If not, Im fucked.
---------------------------------------------

If I clip my soundcard outputs..I can reduce my master volume in my software...
If i clip my mixer channel... I can turn down my soundcard output level...
If I clip my D/A converter... I can turn down my mixer...
If I clip my speakers, I can turn down my amp.


Please note.. when you are playing back a file, it needs to be amplified somewhere so that you can HEAR it..(1s and 0s make no noise..)... and you can have all the same problems with clipping that you had when you were recording. And when you are recording you may hear clipping that isnt being recorded... say if you were clipping your montiors.

Also note. There are many MORE places to get distortion than those listed.

My soulution.. many meters. I have clip indicators of some kind at.... 8 places from instrument to monitors. but Im anal like that.

xoxo

 

[John Sayers]

also remember a mixer is just that - if you play one track and it's ok and play another and it's ok then MIX them the added signals could clip the output so it's better to turn them down at the source rather than turn down the mixer output.

cheers
john

 

[Emeric]

1. Yeah, assuming it's hot enough.

2. If the distortion is really there, no amount of fader movement is going to get rid of it. So as camn says, it's distorting somewhere else. If I record a digitally clipped track and turn down the fader, I get a quieter, digitally clipped track.

3. It's distorting somewhere else in your signal chain. Whether it's in the virtual chain (DX effects on the inserts or bus, main stereo output bus) or the outputs of your soundcard. I suspect it's in virtual software land, since you can eliminate it by turning the faders down it can't be a problem at the input side. Unless CEP has some funky anti-distortion function.

 

[drstawl]

I'll just chime in with the simplistic fact that the clipping should be tracked down at the track level.
Sure it can occur at the mix level, but you have to track it down at the track level FIRST. If it ain't there then you've messed up the mix. Just back off some of the levels on the individual tracks and you'll be OK.

 

[S8-N]

"Clipping" will give you that "POP" in digital recording... And you will hear it. Its loud. Its ugly... Having the levels of your software mixer too high shouldnt result in clipping... having the signal level going into your soundcard WILL result in clipping.
If you are hearing distortion I would say it is most likely from the preamp. It could be from the mic itself, but only if you are pushing some serious air into it.
If the signal going into the soundcard is too hot, it wont distort... it will clip...
If moving your software faders down eliminated the distortion... then maybe it is your speakers distorting... because I see no way for a software mixer to create distortion from the levels being too high.

Maybe I am just wrong, too.

 

[Tom Hicks]

clipping refers to transistor op amps slicing off the top of the waveform which produces an particular unmusical distortion with emphasisi on the odd harmonics (tube distortion is even).
But digital "distortion" is more accurately known as an "over",meaning over zero dB at the digital input point.The difference is significant.
In the olden jarassic days of slamming levels to tape,it was desireable to feed the recording deck a hot a signal as possible.You got compression,sustain and "warmth" as nifty artifacts.You have to be super careful with digital to avoid this possibility because the pops,clicks and bursts of noise produced are really awful.
Here's the point.Back when we HAD to slam levels because the headroom (or dynamic range)was so narrow.But is that the case now?No way!We've got headroom out the wazoo, so there is no practical reason to play it dangerously close to the edge.Unless you want to get into a pissing contest of "my CD is louder than yours".

Tom