Mixing musicals and plays has been a passion of mine for many years and I've been very lucky to have mixed a lot of shows over that time both analogue and digital desks, and even though the technology has changed, the style of mixing hasn’t.

It’s this style of mixing that people ask me about the most. 

The style I’m talking about is line by line mixing.

Line By Line Mixing Explained

Simply put, line by line mixing is when the sound operator turns on a mic when a line is said and turns it off when the line is finished.

There are 3 different ways I’ve seen sound engineers mix line by line, but before I get into that, what is the different between mixing your favourite band and mixing a musical?

Band vs Musical

Mixing a musical and mixing a band are different because of 6 main factors. These these factors are, Vocalists, Dynamics, Time Delay, Desk Cues, Mics and Mixing Style.


A band normally has a lead singer, with the bass player and drummer joining in and a few backing singers for good measure.

A muscial could have 40 to 50 singers on the stage at one time, all singing different lines in the song.


In a musical the dynamics of a song can change a number of times, this could be due to dialogue within the song or because the director and sound designer want to create a certain emotion for the audience.

A band doesn't normally have that many dynamic changes.

Time Delay

There isn't normally much need to change the delay time on the lead singer of a band unless they move from the front of the stage.

In Musical theatre, the singers get every where, front, back and sides and this can be a nightmare.To cope with that, some designers change the delay time on the singers. This can be done via the singers desk channel or via a vocal group. The designer could allocate 3 groups for each vocal zone and have different delay times. (see diagram) The operator would watch the actors and change the desk cue when the actors moved from from zone to zone.

Mixing line by line delay times

Desk Cues

Musical songs have more desk cues than band songs as there are more dialogue bits, time delay changes and reverb changes. A band may have a desk cue for each song in the song set. That could be 15 to 17 cues. A musical theatre show could have over 300 desk cues.


Most bands use the good old SM 58 microphone or other similar handheld mic. Musicals use hairline, boom and handhelds mics. This changes the way the show is mixed.

Mixing Style

For a band you normally push all the mics up and do small qweaks for each song.

For a musical, you mix each line as it's said. Over the years I have come across three styles of line by line mixing. 

Mutes, Automation and Fader.

Mutes, Automation or Faders.

Using Mutes

Some engineers use the mutes. This method is a bit harsh and I don’t really consider it as mixing.

The sound op unmutes the mic just before the line is spoken and muted again once the line is said.

This way of mixing could be used on a small show that doesn’t have a sound engineer and uses a stage manager to fire the lighting and sound desks at the same time. This style doesn’t work well as it relies heavily on the actor saying the line at exactly the same level every time.

Using Automation

A similar way of mixing uses automation on a modern digital desk. This works well for pre-recorded tracks as the tracks are the same level every show. Again, it doesn’t work that well with real life actors, only because they aren’t as consistent as recorded tracks.

Using Faders

This is the most common way sound engineers use to mix. The operator pushes or pulls the faders as each line is said to balance the actors or singers. This is great for live shows as the sound engineer has more control and can adjust the volume quickly.

Why are musicals mixed line by line.

boom mic - line by line mixing

Sound design for musicals can be slightly different to plays, TV or films, as they normally use hair line mics or mics attached to ear hangers.

Plays, TV and Films

Plays usually use mics attached to the front of the stage called float mics and TV and films use boom mics which are held over the actors, just out of shot.


In a musical, the mics that are used are small personal mics that are normally the size of the nail on your little finger. They are normally placed either in the hearline or on a boom as shown.

These mics are attached to transmitters and are called radio or wireless mics

They are normally are fitted before the show and are constantly checked and monitored by a mic runner.

Large musicals can have as many as 70 radio mics in the production and a scene might have 20 actors on stage saying or singing a line, that means there are 20 mics being used.

Having 20 mics up at the same time would create certain acoustic problems like feed back and would reduce clarity, so mixing every line when it happens helps with reducing these problems.

I recently worked with an American producer who was putting on a brand new show and after the first tech run, they asked why a couple of lines where missed. I explained that the lines were missed because I hadn’t seen the show before and I was a little slow on the fader.

They were confused and asked why were the mics off when the actors were on stage.

 I explained and demonstrated line by line mixing as it was an unfamiliar mixing style to them and it blew their minds. They told me that in the last show they had produced, every mic was live and the actors were told not to talk.

choose your image

What effects line by line mixing?

Stage direction, hats, EQ and compressors can all effect how you mix each line. 

Stage Direction

Where the actors are placed on stage matters when mixing. The closer the actors the tighter your mixing has to be.

Sometimes the actors are so close for example, during a fight or love scene, it’s best to use just one mic and adjust it accordingly. 

Hats and EQ

When an actor wears a hat, the sound designer may decide that actor needs a different EQ. 

This new EQ may now sound great for the actor wearing the hat but not so great for anyone else speaking close to that mic.

Mixing each line separately will help reduce the time the hat mic is live and picking up other actors. 


With the more advanced digital desks comes the capability of having a compressor across everything, (which in my opinion isn't always a good thing.)

That means you can have two singers in a scene singing the same song but at different levels. When they are placed at different ends of the stage this isn't a problem. 

The problem arises when again they are close and “screaming down each other’s mics” as I like to say. 

The louder singer could trigger the compressor of the softer singer which could mean the sound engineer loses one of the singers. 

To be honest, there isn’t much you can do in the situation other than speaking with the director and actors either to cheat the positions on stage or sing quieter.

Benefits of line by line mixing

There are a number of benefits to mixing line by line.

The main benefit is because each actor has their own mic and channel, the sound designer can EQ and compress them separately, leading to a smoother and nicer sound.

Another benefit is the sound engineer has more control over each mic and line. This can be really important when you have two or more actors who speak or sing at different levels.

The sound operator can push or pull the faders to balance the actors, also known as line by line mixing.

This style of mixing will always sound tighter and clearer than leaving all the mics up and hoping for the best.

Downsides of line by line mixing

The main downside of line by line mixing is when you are new to the show and have to read the script and you can make more mistakes and miss lines.

Also, when you are reading the script, you are not really listening to the show as much as you should, meaning it could be a bit choppy and louder or quieter than the sound designer or producers would like.

This can be remedied very quickly with a multi track recording of the show.

Line by line mixing and Multi Track Recordings

A multi track recording is a recording of very mic on the sound desk.

Multi track recordings are very useful and can be used as a mixing teaching tool where the sound engineer can practice the mix in the empty theatre without the cast, band or audience.

A multi track recording it can also be used as a reference aid, for example a cast member may be having trouble hearing something in the fold back.

We can use the recording to find out what the problem may be.