The Science of Sound in Film — Film Sound Recording for Beginners

Summary

This episode of 'The Shot List' explores the critical role of production sound in filmmaking, emphasizing the importance of high-quality audio. It delves into sound physics, microphone types, and recording equipment, highlighting the dual-system setup for superior sound capture. The script introduces key sound department roles, from sound mixer to boom operator, and underscores the collaborative effort required for exceptional in-set sound recording, crucial for a film's success.

Takeaways

• 🎥 **Film Production Hierarchy**: Films are composed of sequences, which in turn are made of scenes, and scenes consist of shots.
• 🔊 **Importance of Sound**: Sound quality is crucial; audiences are more forgiving of poor image quality than poor sound.
• 🎬 **Historical Context**: Synced sound in movies has been a pursuit since the late 1920s, emphasizing the role of sound in filmmaking.
• 🌐 **Sound Basics**: Sound is an acoustic wave created by a disturbance, with humans able to hear frequencies between 20 Hz and 20 kHz.
• 🎤 **Microphone Function**: Microphones are transducers that convert sound waves into electrical signals, crucial for recording on set.
• 📊 **Digital Conversion**: Analog signals captured by microphones are translated into digital signals through a process measured by sampling rate.
• 🔍 **Sound Quality Metrics**: Sample rate and bit depth are key factors in recording sound quality, with professional standards often exceeding 48 kHz.
• 📹 **Recording Systems**: Professional sets prefer dual-system recording for higher audio quality, separating audio capture from the camera.
• 🎙️ **Microphone Types**: Different microphones, such as shotgun mics and lavaliers, are used for various purposes based on their polar patterns and sensitivity.
• 🔄 **Signal Processing**: Preamplifiers are used to boost microphone signals to line level, reducing noise interference in the process.
• 🔌 **Cable Types**: Balanced cables like XLRs minimize noise over long distances, unlike unbalanced cables which are more prone to interference.
• 👥 **Sound Department Roles**: The sound mixer, boom operator, and sound utility each play distinct roles in capturing and managing on-set sound.
• 📝 **Documentation**: Sound reports are essential for post-production, providing detailed information about each recorded track.
• 🛠️ **Equipment and Adaptation**: Sound mixers must have extensive knowledge of sound and recording equipment, adapting to various filming conditions.

Q & A

What are the fundamental components of a film's structure?

The fundamental components of a film's structure are sequences, scenes, and shots. Sequences are made up of scenes, and scenes are made up of shots.

What is the significance of sound quality in the film industry?

Sound quality is significant because audiences are more likely to forgive bad image quality than bad sound. Sound is considered half the picture and is crucial for a film's success.

What is the basic principle behind the creation of sound waves?

Sound is a disturbance that creates an acoustic wave through an elastic medium like liquid, gas, or solid. This disturbance comes from a sound source, which prompts vibrations in its surroundings.

How are sound waves measured in terms of frequency?

Sound waves are measured in frequency using the unit hertz, which is the number of times per second that a sound wave repeats itself.

What is the role of a microphone in recording sound?

A microphone is a transducer that converts sound waves into an electrical signal, allowing the capture of sound for recording purposes.

What is the difference between analog and digital signals in sound recording?

Analog signals are the original sounds captured by microphones, while digital signals are the converted form of these sounds, achieved through a process measured by sampling rate.

What is the minimum sampling rate used by most sound mixers and why?

Most sound mixers won't record at a sampling rate lower than 48 kilohertz because it provides a good balance between quality and file size for recording sound accurately.

What does bit depth refer to in sound recording and why is it important?

Bit depth refers to the number of values an amplitude of a sound possesses. It is important because more bits allow for a greater dynamic range and better sound quality.

What are the two main systems for recording sound in film production?

The two main systems for recording sound are the single system, where audio is captured directly onto a camera, and the dual system, where audio is captured independently from the camera for higher quality sound.

What is the purpose of a shotgun microphone and how is it typically used?

A shotgun microphone is a highly directional microphone that mainly picks up sound where it is pointed. It is typically mounted onto a boom pole, allowing a boom operator to get the mic closer to the subject.

What is the role of the sound mixer in the film production process?

The sound mixer, also known as the sound recordist, is in charge of capturing sound on set, communicating with other departments, hiring team members, and ensuring the quality of the recorded sound. They are also responsible for the equipment used on set.

What is the purpose of a lavalier microphone and how does it differ from a shotgun microphone?

A lavalier microphone is a small, hidden microphone used for wide shots where a shotgun mic cannot be close to the subject. It differs from a shotgun microphone in that it has an omnidirectional polar pattern and lacks the frequency balance of higher quality microphones, making it less ideal as a sole audio source.

What is a preamplifier and how does it contribute to sound recording?

A preamplifier is a device that helps avoid noise interference by boosting the weak electronic signal from a microphone up to line level. This is necessary because microphones output a mic level signal that is too weak for other recording and mixing equipment.

What is the difference between unbalanced and balanced cables in terms of noise interference?

Unbalanced cables have two wires and are more prone to noise interference, making them less ideal for long distances. Balanced cables, like XLRs or TRSs, minimize unwanted noise and are more often used on film sets.

What is the role of the boom operator in a film production?

The boom operator is responsible for physically holding the shotgun microphone in a position where it can best capture sound. They are the representative for the sound department on set and prioritize capturing dialogue with minimal handling noise.

What is the function of a sound utility in the sound department?

The sound utility acts as support for the rest of the sound team, running cables, charging batteries, organizing gear, and distributing Interruptible Foldbacks (IFBs) to crew members who need to hear the recorded sound.

What is the importance of a sound report in post-production?

A sound report provides post-production with essential information about each recorded track, including file names, channels, scene, take number, starting timecode, length, and notes. This information is crucial for the editing and sound design process.

Outlines

00:00

🎥 Introduction to Production Sound

This paragraph introduces the concept of production sound as a crucial element in filmmaking, emphasizing the importance of sound quality over image quality. It mentions the historical significance of sound synchronization in films since the late 1920s and highlights the role of on-set sound capture. The paragraph also touches on the basic physics of sound, including its measurement in frequency (hertz) and the human hearing range. It explains the function of microphones as transducers and the digital conversion process involving sampling rates and bit depth, which are key to sound recording quality.

05:04

🎤 Sound Equipment and Techniques

This section delves into the various types of microphones used in film production, such as shotgun mics, lavaliers, and their respective polar patterns and applications. It discusses the single-system and dual-system sound recording methods, with a focus on the professional preference for the latter due to higher sound quality. The paragraph also covers the role of sound recorders, the importance of preamplifiers in boosting signals, and the distinction between mic level and line level. Additionally, it addresses the use of cables, wireless transmitters and receivers, and the practice of pre-fader listen to isolate and diagnose sound issues during recording.

10:05

👥 The Sound Department and Its Responsibilities

The final paragraph outlines the roles and responsibilities of the sound department in a film production. It describes the sound mixer's or sound recordist's duties, including early involvement in pre-production, script breakdown, and collaboration with other departments. The paragraph also explains the importance of the boom operator in capturing dialogue and the role of the sound utility in supporting the team. It concludes with the mention of the sound report, a crucial document for post-production, and emphasizes the importance of the sound department's continuous learning and adaptation for the success of a film.

Keywords

💡Production Sound

Production sound refers to the audio captured during the filming of a movie or TV show. It is a critical component of the filmmaking process, as it includes dialogue, sound effects, and ambient noises that contribute to the overall atmosphere and realism of a scene. In the script, the theme revolves around the importance of production sound and the various techniques and equipment used to capture high-quality audio on set.

💡Sound Mixer

A sound mixer, also known as a sound recordist, is the head of the sound department on a film set. They are responsible for capturing and controlling the audio during filming. The script emphasizes the role of the sound mixer in coordinating with other departments, making crucial decisions about microphone placement, and ensuring the quality of the recorded sound, as highlighted by the line 'The head of the sound department is the sound mixer, otherwise referred to as the sound recordist.'

💡Microphone

Microphones are transducers that convert sound waves into electrical signals. The script discusses various types of microphones, such as shotgun mics and lavaliers, which are used to capture different aspects of the sound in a scene. Microphones are essential tools for a sound mixer, as they determine the quality and directionality of the captured audio.

💡Sampling Rate

Sampling rate is the number of times per second that a sound wave is sampled during the conversion from an analog to a digital signal. It is measured in kilohertz and affects the accuracy and quality of the recorded sound. The script mentions that most sound mixers won't record at a sampling rate lower than 48 kilohertz, indicating the importance of a high sampling rate for professional audio recording.

💡Bit Depth

Bit depth refers to the number of values an amplitude of a sound possesses, which affects the dynamic range of the audio. The script explains that more bits allow for a greater dynamic range, with sound mixers typically recording with at least 16 bits to capture a wide array of sound values.

💡Single System

A single system is a setup where audio is captured directly onto a camera. The script contrasts this with a dual system, noting that while a single system is compact and pre-synced, it may sacrifice audio quality, which is why most professional sets prefer the dual system approach.

💡Dual System

A dual system is a recording setup where audio is captured independently from the camera. The script highlights the benefits of the dual system, such as allowing for higher quality sound capture and the use of various microphones placed closer to sound sources.

💡Recorder

A recorder is a device used in the dual system setup to intake sound captured by microphones and allows the sound mixer to control levels in real-time. The script provides examples of different types of recorders, from simple devices like the Zoom H5 to more elaborate systems used by professional sound mixers.

💡Polar Pattern

The polar pattern of a microphone describes its directionality, or the area in which it mainly picks up sound. The script uses the term to describe the directionality of shotgun microphones, which have a low bar polar pattern, meaning they are highly directional and pick up sound primarily where they are pointed.

💡Lavalier

Lavaliers are small, hidden microphones used on or near a subject to capture dialogue, especially in wide shots where a shotgun microphone cannot be used. The script explains that while lavaliers are common, they lack the frequency balance of higher quality microphones and are often used as a backup audio source.

💡Preamplifier

A preamplifier is a device that boosts the weak electronic signal from a microphone up to line level, helping to avoid noise interference. The script discusses the importance of preamplifiers in the sound recording process and how they are generally built into sound recorders with presets for mic and line levels.

Highlights

Films are composed of sequences, scenes, and shots, each requiring careful sound design.

Audiences are more forgiving of poor image quality than poor sound quality.

Sound is considered 'half the picture' by George Lucas, emphasizing its importance in filmmaking.

Sound is a physical disturbance creating waves through elastic mediums.

Humans can hear frequencies between 20 hertz and 20 kilohertz.

Microphones are transducers that convert sound waves into electrical signals.

Sampling rate and bit depth are critical parameters in sound recording quality.

Single system recording captures audio directly onto the camera, while dual system records audio separately.

A sound recorder is essential for dual system setups, controlling sound capture and levels.

Shotgun mics are highly directional and often used on boom poles to capture sound close to the subject.

Condenser mics are sensitive and require phantom power, unlike dynamic mics.

Lavaliers are small, hidden mics used for wide shots and as backups, but lack frequency balance.

ENG-style kits, or two and a boom, are common on smaller sets and include a shotgun mic, lavaliers, and a recorder.

Preamplifiers boost weak signals from microphones to line level, reducing noise interference.

Cables can be unbalanced or balanced; balanced cables like XLRs minimize noise over long distances.

Sound mixers use pre-fader listen (PFL) to isolate and diagnose sound tracks without altering the mix.

The sound department, led by the sound mixer, is crucial for the success of a film's audio.

Sound mixers often own their equipment and are involved from pre-production, ensuring sound quality from the start.

Boom operators are responsible for physically holding the shotgun mic to capture dialogue.

Sound utility crew members support the sound department with cable management and equipment organization.

A sound report is filled out at the end of each day to provide post-production with detailed recording information.

Good sound requires meticulous planning and a deep understanding of both sound and recording equipment.

Transcripts

Films are made up of sequences.

Sequences are made up of scenes.

And scenes are made up of shots.

In previous episodes, we covered lighting, composition, and animation.

In this episode, we'll dive into the world of production sound.

- Boom mic. - We got a boom mic.

- It's a boom mic.

- This is episode 16 of 'The Shot List'.

Production Sound Part 1.

Before we get started, don't forget to subscribe to StudioBinder and

turn on notifications to stay in the know on all things filmmaking.

Let's speed.

- All right, roll sound. - Speed.

- There is an oft-cited adage in the film industry.

Audiences will forgive bad image quality, but will never forgive bad sound.

Since sound began being synced with movies in the late 1920s, filmmakers have pursued

audio that augments what an audience sees.

As George Lucas has noted, sound is half the picture.

And sound often begins with what is captured on set.

But in order to record sound well, one must know the basics of its physics.

At its essence, sound is a disturbance that creates an acoustic wave through an elastic

medium like liquid, gas, or solid.

This disturbance comes from a sound source, which prompts

vibrations in its surroundings.

Sound waves can be measured in frequency using the unit hertz, which

is the number of times per second that a sound wave repeats itself.

Humans can hear between 20 hertz and 20 kilohertz.

To record sound, we use microphones.

Transducers that convert sound waves into an electrical signal.

Different kinds of microphones use different methods to create the

signal, which we'll cover in a moment.

Today, the analog signals captured by microphones are

translated into digital signals.

This conversion is measured by sampling rate.

The amount of times a sound wave is sampled when it's being

turned into a digital signal.

The more samples taken, the more accurate the sound will be.

Sample rate is measured in kilohertz, though it is not

to be confused with frequency.

Most sound mixers won't record at a sampling rate lower than 48 kilohertz,

and many will record at higher rates, like 96 or 192 kilohertz.

Sound mixers must also take bit depth into account.

This refers to the number of values an amplitude of a sound possesses.

Fewer bits sound like this.

While more bits allow for more dynamic range.

Typically, a mixer will record with at least 16 bits, which

captures 65,536 values.

The physics of sound only scratches the surface of the knowledge

a sound mixer needs to have.

- What do you want with theory alone?

- Let's look at some additional sound terms.

Many of the terms you may hear in the sound department on set refer

to various pieces of equipment.

First, there is the single system versus the double or

dual-system for recording sound.

A single system is when audio is captured directly onto a camera.

This makes for a compact setup that is quick and pre-synced for an editor.

But most professional sets will use the dual system, where the audio is

captured independently from the camera.

This typically allows for higher quality sound, since microphones can be placed

closer to sources and the recorder can capture in a higher fidelity.

No matter the set, a dual system setup requires a recorder.

This device intakes the sound being captured by microphones.

While also allowing for the mixer to control levels in real-time.

A recorder can be as simple as a Zoom H5.

Or as elaborate as sound mixer Tom Curley's.

- I'm using the Sound Devices 688 and CL12 system right now.

- These larger systems typically require a sound cart, which holds

the various equipment a sound mixer needs while still being mobile.

A sound mixer has several different types of microphones to choose from.

The most common is the shotgun mic, a highly directional microphone that mainly

picks up sound where it is pointed.

A shotgun's directionality can be described through its

polar pattern, which illustrates decibels and distance.

A shotgun has a low bar polar pattern.

Shotguns are usually mounted onto a boom pole, which allows a boom operator

to get the mic closer to the subject.

A shotgun can be either a condenser mic or a dynamic mic.

A condenser is generally more sensitive and requires phantom power to boost its signal.

This is different from a dynamic mic, which is better

for capturing and isolating a very close sound source.

And it does not require phantom power.

Lavaliers, however, are very common on set.

They are small microphones which can be hidden on or near a subject.

Typically used for wide shots where a shotgun has to be far away.

They can also be utilized as a backup for the shotgun's audio.

But they lack the frequency balance of higher quality microphones.

So mixers often avoid using them as a sole audio source.

Lavaliers have an omnidirectional polar pattern, which means as

long as they are near the subject, they will pick up their sound.

But it also means a mixer needs to be mindful of avoiding the noise of clothing.

On smaller sets, a sound mixer may have what is called an ENG-style kit,

otherwise referred to as two and a boom.

This setup includes a shotgun microphone, two lavaliers, and a recorder.

On a higher budget set, however, a sound mixer will typically have

a much wider array of equipment.

Sound mixers will also use a preamplifier.

A device which helps avoid noise interference by boosting the

weak electronic signal from a microphone up to line level.

Line level is the signal used by other recording and mixing equipment and has

a level of plus 4 dBu to minus 10 dBu.

Microphones output what is known as mic level, which is minus 35 dBu for condenser

mics and minus 60 for dynamic mics, meaning that both require amplification

to boost them up to line level.

A preamp is generally built into a sound recorder and has two

important presets, mic and line.

With mic selected, the preamp will accept a mic-level signal

and boost it up to line-level.

With line selected, the preamp will accept a line level signal.

This setting can be used to add gain to a line level signal.

Production sound mixer Michael Carmona explains.

- There is always noise.

If I stop talking right now, that's your noise.

My speaking is the signal.

You want much more signal than noise

as much as possible without distortion, without clipping.

- Noise can be minimized through a mixer's choice in cables.

Cables can be divided into two categories, unbalanced and balanced.

Unbalanced cables have two wires and can acquire more noise interference, making

them less ideal for long distances.

For this reason, balanced cables like XLRs or TRSs are more often used on film sets.

Though they are usually more expensive, they minimize unwanted noise.

Some equipment, like lavaliers, can't be connected via cable.

For these situations, mixers use transmitters and receivers, which send

and receive signals from wireless mics.

Receivers can pick up interference.

And so they are usually only used if necessary.

Often, a mixer will want to isolate certain soundtracks as they are recording.

To do this, a mixer will use a pre-fader listen.

Or PFL.

This allows them to diagnose any potential sound issues without altering the mix.

These are only a portion of the large swath of sound equipment that may

be employed on a professional set.

Let's look at the people who use all the equipment.

The sound department.

All the equipment in the world is useless without a talented sound department.

Their roles on set can sometimes be taken for granted, but

they are crucially important.

The head of the sound department is the sound mixer, otherwise

referred to as the sound recordist.

They are in charge of communicating to other departments, as well as

hiring other members of their team.

A sound mixer will usually try to get involved with a shoot early,

often during pre-production.

As production sound mixer Simon Hayes explains.

- If we collaborate early in pre production, we can have our voice heard.

If we can present a workflow that is logical and creates confidence before

we start shooting, directors and actors are always going to be open to that.

A mixer will typically do their own script breakdown, noting how

many characters and potential challenges are present in each scene.

Many mixers will color code dialogue and then add these corresponding

colors to their mix board so they can adjust levels preemptively.

This kind of adjusting that occurs during a take is called running the knobs.

Where a mixer shifts the gain on a given track for a

particularly dynamic sound source.

- Sir, these orders are from army command.

You have to read them.

- Shall we hold back the second wave, sir?

- No, Major. Hesitate now and we lose. We're 500 yards from victory.

- Mixers are also responsible for deciding how to mic a given scene.

This often means collaborating with the camera department

to understand the framing.

And with the costume department to discuss how lavs can be placed on an actor.

Many production sound mixers are owner-operators.

Meaning they own much of the equipment that they are using on set.

And typically charged for equipment rental on top of their services.

This is a unique position within a crew.

Another important sound department member is the boom operator.

Because the sound mixer will usually be working by their recording station, the

boom operator is often the representative for the sound department on set.

They physically hold the shotgun in a position where it can best capture sound.

Boom operator Ben Ring describes his job.

- Make sure when you can get in tight, you can get in tight.

Watch for shadows, watch for reflections.

It's always the same job as a boom op.

- For a boom op, getting dialogue is almost always the highest priority.

Since it's much easier to add sound effects in post.

The operator's goal is to have as little handling noise as possible.

Which means, avoiding moving their hands on the pole.

Typically, a boom op will try to keep the boom pole level with the shotgun

pointed toward the subject's mouth.

Another position in the department is the sound utility.

This crew member largely acts as support for the rest of the team, running cables,

charging batteries, and organizing gear.

They will often be the ones to distribute Interruptible Foldbacks or IFBs.

Headphones for anyone on the crew who needs to hear the sound being recorded.

Like the director, producers, or script supervisor.

At the end of each day, the sound department will fill out a sound report.

A document that gives the post-production information about each recorded track.

This information usually includes the file names, channels, scene,

take number, starting timecode, length, and any relevant notes.

Getting great sound is a herculean effort.

A sound mixer has to have an encyclopedic knowledge of both

sound and recording equipment, while also having a keen ear for detail.

Sound departments are constantly elevating and adapting.

And in the end, their work is crucial to the success of a film.

In our next episode, we'll look at how the sound team puts all this

knowledge into practice on set.

Both indoors and outdoors.

Getting good sound requires a lot of planning.

Make sure your movie will sound great using StudioBinder's pre-production software.

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Goodbye for now.

And remember, don't forget about the sound guy.