When it comes to successful and great sounding live mixes, it is important to remember that the name of the game is “sound reinforcement”. So what does it mean to reinforce? Well, if you consult Merriam-Webster, you find this answer: To strengthen by additional material and support. In the case of live sound we are supporting and strengthening the vision of our artist so as to deliver it to a large number of persons at once. A great place to start then would be to find out just what that vision is. What is important to them? Do some research. Talk to the artist, and listen to recordings of their music to become familiar with what the end goal should be. This will allow you to gauge how to balance the mix and apply the appropriate amount of reinforcement to its elements.
In addition to becoming familiar with the material, be sure to listen to the music and levels of sound being created from the stage. Don’t forget the concept of reinforcement. If you are in a large venue, it may be that every sound on stage needs to added to the mix. However, if you are mixing in a small venue, like a night club or bar, the stage volume of guitar amps and drums should be loud enough so the only thing that needs reinforcing are the vocals or direct inputs like keyboards and acoustic guitars.
"...the first and most significant level change applied to the inputs of your mixing console."
After considering the “reinforcing” element of the mix, begin by adjusting the mic preamps of each input channel to the desired level. I like this to average +4dBu or -18dBfs depending on if its an analog or digital console. Setting proper input gain with the mic preamp is the most fundamental and effective gain staging element of the mix. This is because it is typically the first and most significant level change applied to the inputs of your mixing console. Also, this level will affect everything after its in the signal chain. If these levels are too low, the noise floor of the input signals could become apparent and not allow that channel to get loud enough in the mix. If the level is too high, preamp clipping could occur and add distorted artifacts to the mix.
Once the preamp levels are set, I then take a “top down, bottom up” approach. Allow me to elaborate. Let’s start with the “top down”. What instrument(s) needs to sit atop the mix? Typically, this will be the lead vocal or vocals. Since the vocal usually needs the most amplification and should musically sit on top of all the other sounds, why not start here. With the vocal preamp level set, raise the lead vocal fader to achieve the desired show level. With the lead instrument now at show level, I know how much headroom I can get out of it and how much room I have to support it with the rest of the mix.
Now, let’s consider the “bottom up”. Just like any structure, your mix cannot stand without a good foundation. This will be made up by the rhythm section of the music. Of course, which instruments make up the rhythm section will vary depending on genre of music and artist but will likely include things like drums, bass and other rhythm instrument parts. While balancing this part of the mix here are a few things to consider:
- Which instrument is going to define the lowest part of the mix? Is it going to be the kick drum? If so, what frequency range will his be? For me, I prefer 45-50Hz. Or, perhaps the bass guitar will define the lowest part of the mix. For the answer, refer back to the overall vision you are working to create.
- How will we make use of the drum overhead mics? Will they provide the overall image of the drums as is often the case in jazz? Or will they be used as a way to capture primarily cymbal crashes while relying on the close mics for most of the drum sounds as is common in a rock mix? Or perhaps a combination of both approaches?
With the rhythm section in place, bring in the remaining elements of the mix. Be mindful of the role each element plays in the mix. What are these inputs adding to it? Are they providing melody, counterpoint, movement, chord structure, or simply excitement to the mix? Also, be aware that instruments with similar sounds will fight for space in your mix. To counteract this, consider either panning like instruments to opposite sides if possible or apply equalization to help separate these elements in the mix. Use of high pass filters is also very effective for defining and cleaning up unwanted rumble. (An in depth discussion of eq is beyond the scope of this writing, but will be explored in a future blog).
"...remember to keep the overall vision of your artist in mind and remember the concept of reinforcement."
After all the elements have been added to the mix be sure to listen to the overall picture. Be sure the “top of the mix” (the vocal) is still clear. Make sure the “bottom of the mix” (the rhythm section) is providing a solid base. It may be necessary to control some instrument’s dynamics to tighten up certain areas and provide more headroom for others. The use of compressors and other dynamics processors can be effective here. Remember, however, there is no substitute for knowing each instrument’s role and taking an active part in balancing them.
Lastly, use panning and time-based effects to maintain and create space in your mix. Panning can be tricky, especially in large or wide venues, as a panning move to one side may rob one side of the audience of that instrument, so be careful with this. Use of reverbs, delays, and other time-based effects processors can create some useful artificial space.
This is just a brief overview of the fundamentals of a live mix. Each of the sections of this blog could easily be elaborated. To recap however, remember to keep the overall vision of your artist in mind and remember the concept of reinforcement. Be sure to set good mic preamp gain for each of your inputs. Keep the lead vocal or instrument sitting on top of the mix musically. Create a good foundation for your mix with the rhythm instruments. Add the rest of the mix elements, being sure to consider their own roles. Maintain the dynamics of the mix while actively balancing the parts. Finally, add dimension to mix with panning controls and time-based effects processors.