Ask the Engineer: Scott Hull on Mixing: Master Buss EQ and Peak Limiting, Part 2

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Ask the Engineer is a series on the Masterdisk blog where our engineers answer questions about music production.

SCOTT HULL is a 28-year veteran mastering engineer and the owner of Masterdisk studios in NYC. Scott started his career in 1983 and has mastered hit records and classic albums in every genre, as well as many Grammy-winning titles. He is widely regarded as an expert in vinyl mastering. Recent projects include albums for Donald Fagen, Sting, Dave Matthews, Glenn Frey and KISS, as well as multiple albums for the Sh-K-Boom, Tzadik and Luaka Bop labels. Over the course of his career Scott has mastered albums for Bob Dylan, Bruce Springsteen, Miles Davis, Lou Reed, Ravi Shankar, Herbie Hancock, Tom Zé, John Mayer Joe Bonamassa, and many more.

Photo of Scott HullQ: When I send my mixes to my mastering engineer should I remove the buss limiting and EQ? (Read Part 1 of Scott’s answer here.)

A: Here are “Scott Hull’s Guidelines for the Use of Buss Processing.”

1. If you have mixed through the buss processing, i.e. had the compressor ON while you were mixing, then you most likely should leave the buss compressor or EQ ON when you send the mix to the mastering engineer.

2. If you find that when you take the buss compressor out the mix “falls apart” or loses it’s soul, then you should probably leave the compressor or effects ON when you create the mix for mastering.

3. If however, you didn’t mix thru the compressor – but added it after the mix to bump up the level for references — in that case you really must take the buss effects OFF the mix when you send it to mastering.

4. If someone else did your mixing and you are not sure if they mixed “through” the buss compressor or not, ask the engineer to print the mix with AND without the buss effects. Please remember too that your final 24 bit mix Does NOT have to be limited to peak at zero.

One other detail. Many times my clients come to me with a mix that has very obvious “flat topped” peak limiting. We call them “bricks” or “Tootsie Rolls” because of the way the waveform looks. At this point I’ll ask for a mix without the limiting, and they respond that they hadn’t put a limiter on the mix. And they hadn’t — but there WAS limiting, it just wasn’t done by a plugin called a limiter. Anytime you raise the level, or combine two or more signals together, or process the signal in a plug in, you run the risk of peak limiting within that component — and in many cases the software doesn’t flag the overshoot. You have to consistently be aware of your internal gain structure through your workstation and keep an ear and eye out for hidden limiting.

It’s like this: if every peak peaks at exactly the same level, then limiting happened.

One more final note: Don’t confuse track compression or limiting with buss compression or limiting. Individual tack by track gain control is not only a good thing — it’s absolutely essential. Oftentimes, when I find someone has overused a master buss compressor they did so because they had not applied enough gain control (compression or limiting) to the individual tracks.

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