Using Reference Tracks with Multiband Compression & MS Processing
The idea of a reference track is to take your final mix and compare it to something you consider to be a reference or a standard that’s a high quality mix and recording in a particular style of music that you’re working on. Sometimes when you listen to your mix compared to the reference you notice things you need to change or improve. A lot of times when I compare my entire mix to the entire mix of my reference, it’s difficult to pinpoint and focus on exact areas I need to fix and improve. My suggestion is to use tools inside your digital audio workstation to break down the reference track and focus on different areas and answer questions about how did the engineer decide to place and balance all the different instruments.
One thing you can use is a multiband processor. I’m using the Waves C6. I’m not actually gonna use it for any kind of compression, what I’m gonna do is use it to break up the signal into a couple different important frequency regions. So let me go ahead and play you back a reference track and show you how I’m gonna use it.
[reference track mix]
This is kind of a pop/rock song. Heavy drums, heavy guitar, bass and vocals coming in. One important question to ask is how are my instruments balanced in the really low frequency region of my mix. So let me crank this up a little bit, you might need to listen on headphones or with a subwoofer, and we’ll just focus on this low frequency region below 75 Hz.
[reference track under 75 Hz]
A question to ask is what instruments are down here, how are they balanced. In this mix I hear a lot of the bass guitar but I don’t hear a lot of the kick drum. What that might tell me is I need to scoop out a little of my kick drum and let the bass guitar occupy a lot of that low frequency region. Another thing to notice is what instruments are not in this frequency region. So you don’t hear any of the guitars, they’ve used a high pass filter above this frequency region to get rid of all that really low muddy information in the guitars. So that’s something to think about, you know, what instruments are not in these different frequency regions for what you need to take out and information you can remove of these different instruments.
Let’s then listen to the low-mids. This is an important frequency region to listen to the balance between things like vocals and guitars.
[reference track + midrange vocals and guitars]
Here I’m focusing on just low mids, how do my vocals compare to all the other sounds. Do I need to boost my vocals on my actual mix because on the reference track the vocals are a particular level compared to everything else?
Same thing with upper-mids. Listen to how the drums and guitars are balanced. How much do the vocals stick out. And then listen to the high frequency region. How do the guitars compare to things like cymbals. As far as those really high parts, how is the engineer deciding to maybe shave off some high end of vocals or guitars, make space for kind of the excitement in the cymbals without making things too harsh. That’s a good way to compare these different frequency regions.
With the C6 you can sweep the spectrum and listen to different frequency regions.
[reference mix + Waves C6 sweeping]
So to focus on things around 140 Hz. If you don’t have Waves C6, another plugin you can use is a stock EQ plugin. In this case I’m using the low pass and high pass filters with a 24 dB octave. Focus on different frequency regions: low mids, upper mids. So even if you don’t have a multi-band processor like C6, there’s tools you can use to spectrally break down these full mixes.
Last thing is using a plugin with mid-side processing. The idea here is to use these tools to take out the information that’s not in the center or sides, and listen for where is the engineer is placing these instruments. Is there guitars all the way out wide but do they show up a little bit in the center? And think about how you want to pan things in your mix.
[reference mix + Waves Center mid-side processing]
You got the information in the center. But you hear there’s a lot of bass, a lot of snare, vocals. Just listen to what’s on the sides. Sounds like there’s still some vocals there but it’s probably a lot of reverb and stereo effects that are being added to it.
Those are a few different ways you can separate information in a mix whether breaking down the frequency regions of your mix or focusing on the stereo field and where you want to place different parts of your mix to match your final mix to a reference mix.