Clipping

[comp15]

I'm nearing the point where I will send my stems to a professional mixer. However, various parts of various pieces (non-vocal; instrumental only) are clipping indicated on DP's mixer interface. It creates of a lot of additional work for me to have to pre-mix because I have to move onto some more work. My question is, can I send the stems to a mixer even if the sounds are clipping here and there? Or, should I fix that prior to sending off the stems?

thanks

[Shooshie]

That depends on whether you're recording at 32 bits Floating Point or 16 or 24 bits. If you can export stems digitally at 32 bits FP, and send those to your mastering engineer, he can probably load them and mix them without clipping.

But there's no reason to do that. It's a lot of extra work for him, and if he's charging you by the hour, you'll soon wish you had done it yourself. There are other ways.

Rather than output each track to Main Out, instead output to an Aux Track. I call mine a Submaster. Bring the level down on the submaster (or Stem or whatever you want to call it), to the point that you get no clipping, and bounce that (or freeze or record or whatever method you use) to disk. There is enough headroom in DP (32 bits FP) to accommodate track overages as long as they don't go back into the analog domain or into a final 16 bit or 24 bit 2-track.

Your track may sound dull and lackluster when you turn down the audio that much, but as long as it's not down too far, your engineer can use it to do what he wants. There are many caveats to what I just said. I'm not going to try to list them all. But if you're lowering the volume too far, you're neglecting a substantial percentage of digital detail which you may prefer to keep. If so, it's better to remix the tracks so that they don't clip in the first place, OR to put a brick-wall limiter on the clipping tracks. Or, you may want to put a brick-wall limiter on the submaster or master track. Each way works, but each has its own subtleties which probably don't matter to anyone but the engineer. I prefer not to clip individual tracks. Period. But when you mix them, there are inevitably places where clipping can hardly be avoided, because two transients come together at the same moment and combine, increasing their power and sometimes clipping. This is good reason to put a brick-wall limiter on the master track, though technically it's changing your mix. If you can bring it down before it is combined, and still get the mix you want, you may find that you're more in control of your sound.

Like I said, it mainly matters to engineers. But if you're clipping all over the place, then it's going to affect the final product, so it does matter to everyone, ultimately.

Short answer:

• The less work your mastering engineer has to do, the better off you'll both be. The right thing is to avoid clipping while you're mixing, keep levels off their hottest values, and produce a solid set of tracks that sound good and technically stay within production parameters. How you do it is up to you, but do the work. The longer you're in control of your sound, the more your artistic vision will be maintained.

Shooshie

[comp15]

If there will ever be a time when I have to recall an instance when a question of mine was thoroughly answered and done so quickly, this is one of those times to which I will reference.

Thank you.

[MIDI Life Crisis]

FWIW, even in my most carefully crafted mixed I will sometimes see clipping and it's almost always an over saturated plug (reverb, etc). Once I track that down (the meter bridge is great for that) it usually clears the clipping. Just a random thought.

[Phil O]

Good advice from Shooshie! Please permit me to add.

For future projects, ask your mixing or mastering engineer how they would like the files. Most will give you their personal preference for levels. The mastering engineer that I use, for example, likes me to keep peaks between -2 and -4 dB. Depending on your engineer's workflow these numbers could vary. After you've done it a few times, you'll get the hang of where to start your mix to get the desired levels (when it's done) with minimal tweaking at the end.

Phil