Why Send Clipped Mixes to the Mastering Engineer?
By Mike Senior
One of the mix engineers I’m following most closely is the urban-pop hit machine Serban Ghenea, and what has recently intrigued me is that he appears to digitally clip his mixes. While such clipping has long been a standard (if contentious) method of loudness maximisation in pop music, the normal received wisdom is that it’s best left to the mastering engineer, who can best judge the impact of its distortion side effects for each track within the context of the whole record. However, if you look at the waveforms of some of the songs Ghenea has mixed, you’ll often see that the flat clipped sections of the waveform are at an angle (as in the example shown here, from Katy Perry’s hit, “I Kissed A Girl”), which implies to me that the clipped audio has been high-pass filtered. High-pass filtering is an extremely common mastering process, but would logically happen well before any loudness maximisation — the fact that it’s not leads me to suspect that Ghenea is actually clipping the file himself.
The big question, of course, is why. The main reason I can think of is the same reason a lot of people compress their master buss during mixdown: because it’s difficult to make appropriate mix decisions without taking the effects of the master processing into account. It’s primarily the drum peaks that are clipped in Ghenea’s mixes, which affects the attack tone of each hit, so maybe Ghenea’s just trying to factor this in when he’s setting his drum EQ.
But why not deliver an unclipped file to mastering and then simply ask the mastering engineer to clip it by a certain number of decibels, say? Who knows? Maybe he just doesn’t trust mastering engineers to do what he wants…
Mike Senior is a professional engineer who has worked with Wet Wet Wet, The Charlatans, Reef, Therapy, and Nigel Kennedy. He has transformed dozens of amateur mixes for Sound On Sound magazine’s popular Mix Rescue column. As part of Cambridge Music Technology, he also provides in-depth training courses and workshops specialising in the documented techniques of the world’s top producers. His new book Mixing Secrets For The Small Studio is a down-to-earth mixing primer that shows how to achieve commercial-grade sonics within real-world project/college setups.