There have been a lot of questions over the last few months asking me how to achieve a warm analog mix in the digital domain and how to reduce high-end harshness. I do have a couple cures for that but let me first reply that I make no distinction between digital and analog formats anymore. As a matter of fact it’s never really one or the other since most recording and mix engineers are using a hybrid system of both formats. “D vs. A” is a dead argument these days since “D and A” is the reality. Now I love my analog boxes but they don’t make for automatic warmth.
The analog tag is misleading too. I’ve heard many cold, sterile mixes and recordings from many mix engineers using the best analog consoles, tube Pultec EQ’s and properly setup 2″ tape machines. Consequently, I’ve heard many others and myself mix gorgeous warmth completely in the digital domain. So lets remove the analog tag as a warm metaphor since bad practices can cause problems in any mix format.
Warm from the start is the best place to begin.
If you haven’t recorded your song yet, the best start for a warm mix is in your arrangement. The instruments and sounds you choose including the key and chord voicing have a direct impact on the amount of high-end in the finished mix. Higher key, higher notes = higher high-end harmonics, but just be aware of it. 90% of the time a key is considered for the singers range and their sweet-spot as it should. Basically, if you record many layers of intruments in the same high octaves, you’ll end up with a lot of high-end energy. It’s not a bad thing if that’s the intention, but you may find difficulty mixing with competing sounds in the same octave and every other element needing space for those frequencies.
With instruments, the tone, timbre and chord voicing matter a bunch. A mistake made by many engineers/producers is to always look for an instrument sound, mic or EQ that “cuts” through the mix. Well, if they record all the sounds to cut through the mix, then nothing will cut through because you’ll end up with a bunch of high-end hash that you’ll be removing from the mix. Kind of backwards and definitely a pain in the butt. Generally, pick your instruments and chord voicing as if they were EQ choices for your final product.
A simple rule for microphones if you have the option; if the sound you want to record is too bright use a warm mic. If a sound is too warm, use a bright mic. If it is a “softsynth” or VSTi choose the tone and timbre carefully. Do not add high-end EQ to the sound if it’s too muddy, simply cut the mud “a bit”, but under-EQ the record-side input to leave the deeper tweaking EQ for the mix.
As far as my mix EQ’s, my weapon of choice is the “Low Pass Filter” (LPF) This EQ filter is your best friend for getting things warm. I would get familiar with it if you’re not already. Many avoid this filter but it’s very good for putting warmth to your mix, but you need to use them gently and on the few individual tracks that need it. 6 to 3 db pole, or even less, and the right frequency.
I used a bit of low pass filtering on a few tracks on several songs on this record. I also used some straight-up warm plugins in other spots. Regardless, It’s always a mix and match and not one technique. But low-pass filtering is the most basic and simple tool for taking a harsh edge off tough tracks.
Like everything else, you need to use your ears. I’ll tell ya right now, I’ve used them on almost every channel when the instruments are all eq’d too bright. Yes, some people throw high boosted eq on everything. Check this “Low Pass Filter” link for a simplified explanation. Go ahead an throw one on a super high-end crunchy track in your mix and turn the knobs. It will become immediately apparent. Be as gentle or as aggressive as needed. The correct setting are in the ears.