More information on mixing musical theatre

A musical theatre show is quite different to a live band performance: each genre has distinct requirements that are best served by different workflows. When live music is reinforced, unidirectional microphones are typically used and placed as close as possible to each instrument – isolating the microphone from other sound sources. However, in musical theatre the actors are typically wearing sensitive omnidirectional microphones on their heads – these pick up a lot of ambient sound, including the sound of other actors speaking.

When the sound of an actor's voice is picked up by several microphones in close proximity and then mixed together through an audio console, it can result in a degraded sound quality from these interactions. For this reason, the best practice in theatrical mixing is to only have a mic up when it's in use – just when the actor is speaking or singing. By ensuring that mics are only on when they are in use, we help the audience focus on whomever is currently speaking or singing, which ultimately keeps everyone immersed in the story.

Turning a mic down when an actor is not speaking or singing helps reduce or eliminate these undesirable interactions between microphones, reduces overall noise in the mix, and removes noise from actors' mics that are not in the current scene and could be backstage (maybe talking or changing costumes!). In addition to all of this, reducing the number of open mics at any time maximises the sound system's gain before feedback.

While automixers can be very helpful for panel talks and corporate audio applications, they're not particularly useful for musical theatre. Automixers can not understand the artistic or musical considerations of a theatre performance, such as judging the proper balance between lead and ensemble vocals, accommodating dynamics in performances, or anticipating an actor's delivery in the same way a human operator can, which is why automixers are not commonly used in professional musical theatre mixing.

A skilled theatrical sound operator will be able to react to and reinforce subtleties in an actor's performance, often accenting or de-emphasising particular words or even syllables. Noise gates are much simpler: they either open or close depending on the signal level, so they have no idea what they're reacting to, or what they should be reacting to. If the gate threshold is set high enough to shut out mic bleed from other nearby actors, it will not open for quiet or whispered passages. An actor coughing – or another loud noise happening on stage – can open all of the mics at once, and gates aren't smart enough to deal with a situation where two actors are speaking face-to-face, where a human operator would choose one microphone and leave the other turned down.

In addition, the "chopping" sound of a gate opening or closing can be quite noticeable, particularly during quiet moments of a show.

Simply put, because it doesn't work very well. Any sudden volume changes draw the audience's attention to the sound system and out of the world of the story. Apart from potentially clipping off lines when mutes are snapped on and off, the abrupt changes in the noise floor sound quite objectionable, whereas a moving fader is much more forgiving. Since actors are humans (we think...), their performances will vary slightly from night to night, and fader moves allow the operator to adapt to these subtle variations – rather than just slamming mics open when actors enter the stage.

Actors have a dynamic vocal range and won't say (or sing) each of their lines at the same level throughout the show, so some fader adjustments are always going to be required. The level that the actor is delivering, and the level that is artistically appropriate at a certain point in the show, will change constantly – sometimes within a line, or even within a word. In musicals there is also a large difference between the amount of reinforcement required for dialogue compared to musical numbers, and within musical numbers the level of an actor's mic can change dramatically as the song progresses (e.g. solo singing, chorus singing, dialogue with underscoring, more solo singing, etc).

A trained ear and level balancing ability are key skills of a good theatrical sound operator.

Yes! Mixing the show on DCAs (or VCAs / control groups) is the well-established best practice for musical theatre mixing.

This approach eliminates the issues discussed above and brings some great benefits as well – no unused mics open, maximised gain before feedback, no chopping or clipping lines, no abrupt shifts in the noise floor, and greatly reduced or eliminated interaction between mics (comb filtering, sometimes referred to as "phasing"). It allows the operator to react to the natural dynamics of the show and adjust for variations in performances.

It's also a lot more fun: the operator ends up "playing" the console like an instrument, it's a very tactile artistic feeling compared to mechanically firing a cue list. The operator is given room to continually improve the mix as they become more familiar with the show. Here are some videos demonstrating the technique.

Large musical theatre shows are usually mixed line-by-line – throwing a DCA fader up for every individual dialogue line and immediately pulling it down afterwards – to minimise the number of open mics. This can be difficult to achieve for smaller productions especially when actors skip lines or have inconsistent timing. When using headset mics in a high gain before feedback environment it's sometimes possible to cheat and mix dialogue sections in blocks, essentially leaving the mics for characters on the current script page open rather than throwing every line. However it's always best to tightly mix the show whenever possible, particularly during musical numbers that require lead vocals to be balanced against ensemble vocals.

Further reading:

It depends on the complexity of the show, the number of wireless microphones, and the amount of additional automation required, but it's common for a 2½ hour musical to contain 50 to 100 DCA assignment cues.

When planning out cues it can be useful to think in terms of French Scenes. Every character that speaks on stage will need to be assigned to a DCA in a cue, so a good starting point is to create cue points when several characters enter or leave the stage. These cue points can then be refined based on the dialogue flow in the script – some scenes may have lots of characters speaking necessitating multiple cues, others may not introduce any new speaking characters so no cue is required. Musical numbers usually require separate cues.

The general aim is to create just enough cues for the show: too many cues can result in excessive go button hits, not enough cues can result in lingering stale DCA assignments. The cues should be structured in a way that allows the operator to have the mics they need under their fingers at the correct time.

There are two main schools of thought on this. The first is to keep the same characters consistently assigned to the same DCAs as often as possible, and the second is to assign DCAs in script order for each scene (first character to speak on 1, second to speak on 2, etc).

Maintaining consistent DCA assignments for each character helps ingrain a spatial mapping so fader throws become repeatable, it's also more reliable if the operator accidentally loses their place in the show and has to fall back to muscle memory. Characters are usually assigned to DCAs based on their importance in the show, i.e. the main lead gets 1, the next lead gets 2, etc. However this can be problematic in dialogue scenes with characters delivering lots of one-liners – the fader throws end up all over the place.

Assigning DCAs in script order can be useful for fast-paced dialogue – just throw the faders in order from left to right – but it has some drawbacks. It usually requires additional programming compared to the first method, it relies on the cast accurately reciting their lines in every performance, and there is no safety net if the operator accidentally loses their place in the show.

In general the first method (consistent assignments) is preferred most of the time, but the second method (script order) can be a useful tool when a show has a few busy dialogue scenes. Additionally, it helps to keep ensemble groups assigned to the right-most DCA faders – balancing leads against ensembles is much easier when the faders fall under separate hands.

Occasionally neither method works so a scene or musical number has to be programmed completely ad hoc... the rules can be bent where it makes sense!

Although it would certainly be nice to have more DCAs, on larger consoles DCA 11 and DCA 12 are typically used for band and reverbs, so ten DCAs or less end up being used for wireless microphones. Plus – we only have 10 fingers, so there are diminishing returns!

To allow all 8 DCAs to be used for wireless mics whilst maintaining control of band and reverb levels on X32/M32 consoles, TheatreMix can gang the band subgroup with the LR fader (see LR fader ganging feature guide), and the console's user-assignable encoders can be configured to control reverb send buses. On other consoles, a custom fader layer could be used to position the band and reverb subgroups next to the DCA faders.

For scenes with many solos, it might be helpful to compress ensemble members to a single DCA, or group several soloists together.