Introduction to mixing orchestral music
So you have just received your files from your recording session and it’s time to move on to the next step: mixing your track. The mixing process involves making slight adjustments and enhancements to really bring your track to life and make it sound as amazing as possible. Orchestral recordings from professional studios, such as the ones from Musiversal, usually don’t require too many adjustments, just a few little tweaks here and there.
However, information on mixing for orchestral music with live instruments can be difficult to find. Luckily, here at Musiversal we have a number of experienced audio engineers who are here to help! I tapped into their minds to find out some of the tips, tricks, and techniques they have to help you put the finishing touches on your tracks.
In music, reverb is the effect of soundwaves interacting with objects in a room. When it comes to mixing your orchestra recording, reverb is one of the most crucial considerations. “In the classical music field, one of the most important steps is the reverb amount that is implemented to your piece because it represents your room environment,” says Musiversal audio technician Tomás Quintais.
For adding reverb to your mix you have two options: artificial reverb where you use the reverb features in your DAW or external plugins; or natural reverb, which is the room ambiance recorded directly from the mics in the room with the orchestra.
When it comes to artificial reverb there are two types available: convolution reverb and algorithmic reverb. Convolution reverb involves recording the signals from sounds, such as a click or gunshot, live in a room to recreate the acoustic conditions of that room. This gives you the impulse response of the room which can then be applied to any sounds. This results in a very realistic and accurate reverb sound. On the other hand, algorithmic reverb involves using a pre-programmed algorithm to recreate the acoustic conditions of a space artificially.
When it comes to mixing an orchestral track it is often unnecessary to add artificial reverb at all, especially if you want to keep the mix as close to the original recording as possible. Sometimes it is possible to just use the room ambiance and boost that until you think it sounds good. Usually in a recording session there will be mics set up further from the instruments which will have a wetter sound. You can use these boost the room ambiance by layering them on top of the more close up mics.
Along with reverb, panning is probably the next most crucial part of mixing orchestral music. Panning involves spreading an audio signal in a stereo recording across the left, right, and center. Panning helps to create the effect that a listener is in the room with the musicians watching them play live, with different sounds surrounding them from all sides.
Generally, the goal for panning a studio recording is to recreate where the musicians were sitting in the room. For example, mics from the left-hand side of the room will be panned left and mics from the right-hand side of the room will be panned to the right. This helps to maintain the effect that a listener is in the room with the orchestra and allows space for each instrument.
Of course, as with all mixing techniques, there are no set in stone rules and you are free to mess around with this if you want. There are also some exceptions. For example, if you have a piano in your session you can decide which side to pan the bass notes and treble notes to. The pianist would here bass on the left and treble on the right, so do you recreate this, or how the audience would hear them?
Also crucial to the mixing process is the equalization, better known as EQ. The EQ is what allows you to adjust the frequency of your sound wave. Again for mixing orchestral recordings, EQ is usually used in minimal amounts compared to mixing for other genres. In an orchestral setting, it may be used to remove some of the harsher frequencies from a violin for example. It can also be used to add more clarity to a mix by removing lower frequencies from instruments that may be overpowering other sounds.
There are two different types of EQ plug ins that you can use: Graphic and Parametric. Graphic equalizers often look similar to a traditional mixing board, with many frequency bands. However. you can only control the gain per frequency. Parametric ones usually only have four bands (although sometimes they have more or less than that), but in those four bands you can control gain, frequency, and Q factor (Quality factor).
Musiversal audio engineer Eduardo Mota states that “In my opinion [using a parametric EQ] is a much more versatile process because you can define exactly the frequency that you want and also the bandwidth you want to affect (contrary to the graphic one where you have pre-defined frequency and Q factor).”
Volume Balance and Automation
Volume balance can be used to adjust the volume of individual instruments or mics from the studio recording session. “The volume is one of the most important things because you can "bring to life" something that the musician couldn't do in the recording,” says Mota.
The main use of volume balance is to boost certain parts of the recording that you wish to emphasize. It can also be used to soften other parts to create a contrast. While you can automate most effects with the latest DAWs, volume balance is one of the most useful applications as it allows you to pick the exact sections you want to edit, without it affecting the rest of the track.
Removing Background Sounds
In an orchestral recording session, the mics will capture many other sounds from the room aside from just the sound of the instruments. It is entirely up to you which of these sounds you wish to remove and which ones to keep. Most audio engineers tend to keep sounds that are made while playing the music, such as breaths or the sound of a bow on strings. Sounds that you may want to remove include pages turning or any shuffling noises form musicians moving around.
There are countless other effects that can be used when mixing music such as compression, distortion, and delays. These usually aren’t used when mixing orchestral music, but they may come in useful if you are using an orchestral recording as part of a pop song or film soundtrack. Compression, in particular, should be used very carefully as it will remove the dynamic range from the recording. The broad dynamics of an orchestra are one of its defining characteristics so they should almost always be kept in place.
The best way to learn more about mixing is to listen carefully to other professionally produced music. Pay close attention to how individual instruments are panned, which parts are louder and softer and how the reverb adds depth to the song. Remember that ultimately when it comes to mixing there is no right or wrong - in the end it all comes down to what sounds good to you.