Production Tips: Mastering The Mixdown

Resident studio wizard Dave Pezzner runs us through his process for perfecting his mixdowns in the second of two parts (you can catch the the intro and the first one here).

Focus

In music, sounds love to fight for your brain’s attention. Snares are nasty sounds that demand the midrange frequencies that are important for guitars and lead synths. Kick drums are in constant competition with bass lines, and of course vocals need to take the stage and cut through it all. The frequency range that the human brain can perceive is between 20Hz and 20,000Hz, and while that seems to be a massive range to play with, it’s inevitable that sounds will clash when they cross the same range. As mentioned last week, it’s easy enough to pan these sounds away from each other to give them their own space to fill, but this doesn’t always solve the volume problem in your music. If our aim is to get our song to be nice and loud without the use of limiting, then we will still need to reduce the pile up in these frequency ranges with the instruments that compete with each other. You can see an example of a good frequency chart here.

Sleight of Hand

Sleight of hand is essentially the art of playing with the focus of your brain. A magician will make you look the other direction while the real trick is unfolding. Hence, he didn’t actually pull a coin out of your ear. Your brain, and the brain of everyone watching, was distracted by something else the magician did while he tucked the coin under his palm, only to reveal the coin later, at just the right moment. A brain at ease has tunnel vision and will most often take things at face value, one at a time. We can use this to our advantage when it comes to bringing up the overall volume of our song.

Sounds that reside in the same frequency range will double up in your mix, causing volume spikes in that frequency range. For example, bass sounds will almost always compete with kick drums causing louder spikes while they are playing together. Guitar sounds can sometimes distract the listener from a vocal track. Strings and pads can bury snare drums and percussions. The end result is often times a messy mixdown. We can avoid this problem using a technique called “ducking” and we can do this a number of ways.

Manual Ducking

Before compressors were available engineers had to tailor dynamic range by hand. This involved making level changes in anticipation of the peaks and troughs in the music. This would be the oldest “compression” known to audio engineering, and is still the most tailored to the dynamic range of the human ear: hit record, and automate the faders manually. In my opinion, this is the most interesting way to do it because you can never be perfect at it, and the end result is the inherent mark of the engineer who worked the faders. The benefit is that you have complete control over the volume, however this may not be ideal for shorter elements such as kick drums and percussion.

Removing Unwanted Frequencies

When you are mixing a tune, it’s almost inevitable that you will come across a tone or a ring, some bit of an element that doesn’t sit right with the rest of the song. That is because these harmonics in bass sounds, guitars, drum loops, can be out of tune or register much louder than the rest of the music. This can be an issue when simply turning down the track doesn’t do the job. One quick fix can be to use a band on a parametric EQ and set this band to a higher Q range. Boost that range by about 8dB and slowly adjust the frequency or “sweep” it through the track. The problematic frequency will eventually be highlighted, and boosted. Slowly adjust the frequency until the problem frequency is at its loudest. Then reduce the gain until you no longer notice problems in the audio.

One more thing to watch out for is unwanted sub frequencies. Almost every sound source from contact mics, to analog synths will generate some amount of sub bass frequency. Often times these frequencies are inaudible, but as you sum more and more tracks to the master channel, these lower frequencies will pile up, add unwanted volume and sometimes “mud” to your final master. I typically try to use a parametric EQ band set to a high pass filter to remove frequencies lower than 30-33Hz from bass line and kick drum channels, and that’s easy enough. But for tracks like vocals and guitar, finding that frequency may be a little more challenging.

You don’t want to roll off low frequencies that add body to the sound. In this case I will set the top band of a parametric EQ to “low pass” and reduce the frequency to its lowest setting. Slowly bring up the frequency until you start to hear the lower register of that element. While doing this, it’s important to notice if these lower frequencies compliment or muddy up the low end. Once you start to hear the more useful frequencies of that element, this is the point where you change the “low pass” setting of that band to a “high pass,” and this will remove the necessary amount of bottom frequencies from that instrument.

And there you have it; Seven tricks to make your mixes sound crisper, cleaner, and more importantly, more like what you hear when you’re putting the track together.