Sound Engineering 101: Basics for Event Organizers

Even if you hire professional sound engineers for your events, understanding the basics of sound engineering can significantly improve your ability to communicate effectively with your technical team. This knowledge helps you articulate your expectations more clearly and make more informed decisions about your event's audio requirements.

This beginner-friendly guide explains fundamental sound concepts, terminology, and principles that every event organizer should know.

Understanding Sound: The Basics

Let's start with some fundamental concepts that form the foundation of sound engineering:

What is Sound?

Sound is a pressure wave that travels through air (or other media) and is perceived by our ears. These waves have several important characteristics:

• Frequency: Measured in Hertz (Hz), this determines how high or low a sound is perceived (its pitch). Humans typically hear frequencies between 20Hz (very low bass) and 20,000Hz (very high treble).
• Amplitude: This determines how loud a sound is and is measured in decibels (dB).
• Timbre: The character or quality of a sound that distinguishes different instruments or voices, even when they play the same note at the same volume.

The Decibel Scale

The decibel (dB) scale is logarithmic, not linear, which means that:

• An increase of 10dB is perceived as approximately twice as loud
• A 3dB increase represents a doubling of acoustic power

Understanding appropriate volume levels for different events is important. Sustained exposure to levels above 85dB can cause hearing damage, and many municipalities have noise ordinances limiting permissible sound levels, especially for outdoor events.

The Audio Signal Path

To understand how sound systems work, it's helpful to follow the audio signal from source to speakers:

1. Sound Source: Microphone, instrument, playback device
2. Preamplifier: Boosts the weak signal to a usable level
3. Processing: EQ, compression, effects (may happen at multiple points)
4. Mixing: Combining and balancing multiple signals
5. Power Amplification: Boosting the signal to drive speakers (in powered speakers, this is built-in)
6. Speakers: Converting electrical signals back into sound waves

Key Sound Engineering Concepts

Gain Structure

Proper gain structure – the way signal levels are managed throughout the audio chain – is fundamental to good sound. It ensures:

• Minimal noise
• Maximum clarity
• Headroom for dynamic peaks
• Protection against distortion

When gain structure is poor, you might hear distortion, excessive noise, or insufficient volume – problems that can't be fixed with EQ or other processing.

Equalization (EQ)

EQ allows adjustment of specific frequency ranges within an audio signal. It's used to:

• Correct problems (cut muddy frequencies, reduce harshness)
• Enhance desirable characteristics (add warmth, increase clarity)
• Create space for different elements in a mix
• Compensate for room acoustics or speaker limitations

Common EQ types include:

• Graphic EQ: Fixed frequency bands with boost/cut controls (often used for overall system tuning)
• Parametric EQ: Adjustable frequency, width, and amount of boost/cut (more precise for targeted corrections)

A general rule of thumb: it's usually better to cut unwanted frequencies than to boost desired ones.

Compression

Compression reduces the dynamic range (the difference between the loudest and quietest parts) of an audio signal. It's particularly useful for:

• Controlling inconsistent levels (e.g., a speaker who alternates between whispering and shouting)
• Preventing sudden peaks that could cause distortion
• Creating a more consistent overall volume
• Adding "punch" or density to certain sounds

Key compression parameters include:

• Threshold: The level at which compression begins
• Ratio: How much the signal is compressed (e.g., 4:1 means for every 4dB over threshold, output increases by only 1dB)
• Attack: How quickly compression is applied
• Release: How quickly compression is removed

Feedback

Feedback is that unpleasant howling or squealing that occurs when sound from speakers is picked up by microphones and re-amplified in a loop. Understanding how to prevent and control feedback is essential:

• Microphone Placement: Keep microphones behind speakers and point them away from speakers
• Proper Gain Setting: Use only as much volume as necessary
• EQ Solutions: Identify and reduce the problematic frequencies
• Room Acoustics: Be aware that highly reflective spaces increase feedback risk

Understanding Room Acoustics

The physical space where sound occurs dramatically affects what we hear. Key acoustic concepts include:

Reverberation

Reverberation is the persistence of sound after the original sound has stopped, caused by reflections from surfaces within a space. Different spaces have different reverb characteristics:

• Long Reverb Time: Churches, cathedrals, large halls (can make speech unintelligible)
• Medium Reverb: Living rooms, classrooms (generally balanced)
• Short Reverb: Recording studios, acoustically treated spaces (very clear but can sound unnatural)

Room Modes

Room modes are resonances that occur at specific frequencies based on the dimensions of a room. They can cause certain notes to sound louder or quieter than others, creating an uneven frequency response.

Acoustic Treatment vs. Sound Proofing

• Acoustic Treatment: Materials and structures that improve sound quality within a space by controlling reflections (bass traps, diffusers, absorbers)
• Sound Proofing: Preventing sound from entering or leaving a space (mass, isolation, damping)

For temporary events, you rarely have the option to change a venue's acoustic properties significantly, but understanding them helps you:

• Choose appropriate speaker placement
• Set realistic expectations for sound quality
• Communicate potential challenges to stakeholders
• Make simple adjustments (like adding soft materials in very reflective spaces)

Microphone Types and Techniques

Understanding the basics of microphones helps you communicate more effectively with your sound team:

Common Microphone Types

• Dynamic Microphones: Robust, handle high volume levels, less sensitive (good for loud sources like drums or rock vocals)
• Condenser Microphones: More detailed, require power, more sensitive (ideal for capturing nuance in speech or acoustic instruments)
• Ribbon Microphones: Warm sound, fragile, bidirectional pattern (less common in live sound, more for studio use)

Pickup Patterns

Microphones have different sensitivity patterns that determine from which directions they capture sound:

• Cardioid: Heart-shaped pattern that captures sound primarily from the front (most common for live performance)
• Supercardioid/Hypercardioid: Tighter patterns with some rear sensitivity (good for noisy environments)
• Omnidirectional: Captures sound equally from all directions (good for capturing ambient sound or multiple sources)
• Figure-8/Bidirectional: Captures from front and back, rejects sides (useful for interviewing two people facing each other)

Microphone Placement

Proper microphone placement can make a tremendous difference in sound quality:

• Distance: Closer placement provides more direct sound and less room ambience
• Proximity Effect: Many directional mics produce more bass when used very close to the source
• Angle: Pointing a mic directly at or slightly off-axis from a source affects tonal balance
• Height: For standing presenters, position mics at mouth level, angled slightly upward

Digital vs. Analog Audio

Modern sound systems often combine digital and analog components:

Analog Audio

• Continuous electrical representation of sound waves
• Traditional cables: XLR, TRS, RCA
• Each connection typically carries one audio channel
• Susceptible to noise accumulation over long distances

Digital Audio

• Sound converted to binary data (numbers)
• Uses digital connections: USB, Ethernet, optical
• Can carry multiple channels over a single cable
• Less susceptible to noise or degradation
• Introduces concepts like sample rate and bit depth

Many modern systems use hybrid approaches, with analog microphones feeding digital mixers, and digital distribution feeding analog amplifiers and speakers.

Working Effectively with Sound Engineers

Building a good relationship with your sound team leads to better results:

Communication Tips

• Be specific about issues: Instead of "it sounds bad," try "the vocals are difficult to understand" or "there's too much bass"
• Provide context: Explain the purpose of your event and the audience expectations
• Ask questions: Good engineers are happy to explain what they're doing and why
• Respect expertise: Trust their technical judgments while being clear about your creative vision

Planning for Success

• Advance preparation: Share detailed technical requirements and schedules well before the event
• Allow adequate time: Sound check and system tuning are critical and can't be rushed
• Consider the full picture: Sound, lighting, video, and staging all interact
• Budget appropriately: Good sound isn't the place to cut corners

Conclusion: Sound Knowledge for Better Events

While you don't need to become a sound engineer to organize successful events, understanding these fundamentals helps you:

• Communicate more effectively with your technical team
• Make more informed decisions about equipment and venue selection
• Troubleshoot basic issues and identify when expert help is needed
• Set appropriate expectations for sound quality based on venue constraints

At PiratSwapr, our sound engineers work collaboratively with event organizers, providing not just equipment but expertise and guidance. We believe that an informed client leads to better results, and we're always happy to explain our processes and recommendations.

For your next event in the Czech Republic, let our team help you create the perfect sound environment. Contact us to discuss your specific audio needs and how we can help you achieve them.