Audio engineering fundamentals are the core concepts underneath every tool you use: how sound behaves as a physical wave, how human hearing perceives it, how signals flow through electronics, and how digital audio and processing change them. Learn them first, because they let you predict what any piece of gear or plugin will do, instead of memorizing settings that only work on one song.
Key takeaways
- Audio fundamentals fall into four areas: professional workflow, the physics of sound and hearing, electronics and signal flow, and digital audio, processing and microphones.
- Knowing why a tool behaves the way it does makes decisions faster and tells you right away when something is broken.
- A block diagram is the quickest way to understand gear. On an LA-2A, it shows the gain knob is a simple amplifier, separate from the compression.
- Two relationships go a long way: wavelength equals the speed of sound divided by frequency, and +6 dB doubles a signal's amplitude.
- Andrew Scheps teaches these foundations in the Core Audio Program, a four-course, 40–45 hour, on-demand program for all levels.
What are audio engineering fundamentals?
Audio engineering fundamentals are the principles that explain why recording, mixing and live sound work the way they do. They cover the physics of sound, human perception, electronics and signal flow, digital audio and processing, and the workflow of a professional session.
Andrew Scheps, award-winning mixer, producer and Campus mentor (Beyoncé, Lana Del Rey, Red Hot Chili Peppers), teaches them as a progression in which each layer builds on the one before:
| Area | What it covers | What it helps you do |
|---|---|---|
| Workflow and industry context | Professional roles, studio environments, production workflows | Understand who does what in a session |
| Physics, acoustics and perception | Wave physics, harmonics, room acoustics, how we hear | Make EQ, placement and monitoring decisions based on how sound behaves |
| Audio electronics and signal flow | Circuits, block diagrams, level and impedance matching | Route, gain-stage and troubleshoot any setup |
| Digital audio, processing and microphones | Sample rate, bit depth, dynamics, EQ, effects, mic types and polar patterns | Choose settings, processors and microphones for a reason |
Why do audio engineering fundamentals matter if plugins have presets?
A preset or a quick tip solves one problem on one source. Fundamentals let you solve whole categories of problems, including ones you have never seen, and you work faster because you can predict a result before you reach for a knob.
Scheps put it this way during a free Core Audio info session:
"It's very easy to find a solution to one problem. It's very difficult to find a concept on how to solve a family of problems."
He has taught this material for more than 20 years, starting with a course he developed for UCLA. Even so, preparing the course "made me realize how much stuff I only sort of kind of knew instead of actually knowing it." Filling those gaps changed his daily work:
"And once I knew them, I could make decisions much easier and faster and with a lot more confidence because I knew this should work. And that means if it doesn't work, something's not right, not I don't know what I'm doing."
How does sound work? The physics of sound in plain terms
Sound is a pressure wave traveling through air at roughly 343 meters (about 1,125 feet) per second at room temperature. Five properties explain most of what you hear in a studio.
- Frequency: cycles per second, in hertz (Hz). Human hearing is usually quoted as 20 Hz to 20 kHz, and the top end drops with age.
- Amplitude: the size of the pressure change, which we perceive as loudness.
- Wavelength: the length of one cycle, equal to the speed of sound divided by the frequency. A 100 Hz wave is about 3.4 meters (11 feet) long; a 10 kHz wave is about 3.4 centimeters.
- Phase: where a wave is in its cycle. Two copies of a signal arriving at slightly different times partially cancel, which is called comb filtering.
- Decibel (dB): a logarithmic ratio. +6 dB doubles the amplitude, +3 dB doubles the power, and roughly +10 dB sounds about twice as loud.
Wavelength explains bass buildup in small rooms: in a rectangular room, the first resonance along each dimension sits at the speed of sound divided by twice that dimension. A room 4 meters (13 feet) long resonates around 43 Hz, with more room modes near 86 Hz and 129 Hz. As Scheps told the session, "you could actually measure your room and if it's a rectangle I can tell you what frequencies you're gonna have a problem with. And so can you."
Perception matters just as much. Hearing is less sensitive to lows and highs at quiet levels, so a mix balanced loud can sound thin when you turn it down. That is why The Nature of Sound: Physics, Acoustics, and Human Perception, the program's second course, treats physics and hearing together.
What is signal flow in audio engineering?
Signal flow is the path audio takes from source to listener: microphone, preamp, processors, converters, DAW, and back out to the speakers. If you can trace it, you can route any studio and find any fault by checking one stage at a time.
The companion skill is gain staging: setting the level at each stage so the signal sits well above the noise floor and below clipping. Most noise, distortion and "why is nothing coming out?" moments are signal-flow or gain-staging problems.
Every stage also leaves a fingerprint. In Scheps' words, "all analog gear, no matter what it's supposed to do and what you buy it for, is a noise generator, a harmonic distortion generator, and usually high and low pass filters, because that's what transformers are." Many plugins recreate exactly those side effects.
How do you understand what a piece of gear actually does?
Read its block diagram. A block diagram reduces a circuit to boxes (amplifiers, attenuators, filters) and arrows (the signal path), so you can see what each control touches without being an electronics expert.
In the session, Scheps walked through the LA-2A. The main path runs through a transformer, an optical attenuator, a gain knob and an amplifier. A copy of the audio feeds a second path through another knob, an amplifier and a rear-panel pre-emphasis control, into an electroluminescent driver. "That's a really fancy name for a light bulb. So LA-2As limit audio based on how bright is a light bulb."
Once you see that layout, the controls explain themselves:
"You understand by looking at the LA-2A that that gain knob is just an amplifier. It's a fader. It doesn't affect the compression at all and you can tell that by looking at the diagram. And also you know when it's broken."
The same method works on a Neve 1073: a transformer on the way in, a transformer on the output, and a phase switch near the end of the chain. Scheps notes that block diagrams work for mic preamps, delays, reverbs and even your DAW's mixer, because "it's just boxes and arrows."
How to read a block diagram in five steps
- Find the input and the output. Mark both first.
- Trace the main audio path. Give each block a one-word job: amplify, filter, attenuate, convert.
- Find the control path. This branch, often called the sidechain, measures the signal and tells another block what to do.
- Place every control on its block. Controls on the main path change the sound directly; controls on the control path change how the processor reacts.
- Predict, then test. Before turning a knob, say what should happen. If it doesn't, your diagram or the gear is wrong.
Practice exercise: the one-knob test
Spend 15 minutes mapping one compressor in your DAW, then prove the map with your ears and meters.
- Put your DAW's stock compressor on a drum loop or vocal.
- On paper, sketch its block diagram from the controls alone: input, detector (threshold, ratio, attack, release), gain-reduction element, output gain.
- Set the threshold for about 3 to 6 dB of gain reduction.
- Move only the output gain up and down by 6 dB. Prediction: the level changes, the gain reduction does not.
- Raise the level feeding the compressor by 6 dB with clip gain. Prediction: gain reduction increases, because the detector sees a hotter signal.
- Note anything that surprised you, such as automatic makeup gain. Each surprise corrects your diagram.
If you have an LA-2A-style plugin, repeat the test with Peak Reduction and Gain.
What does the Core Audio Program cover?
The Core Audio Program is a four-course certification program taught by Andrew Scheps. It runs 40–45 hours, is available on demand, and is designed for all levels.
The Core Audio Program follows the progression in the table above:
- How We Work: The People, Places and Process of Professional Audio covers roles, studios and workflows.
- The Nature of Sound: Physics, Acoustics, and Human Perception covers wave physics, acoustics and hearing.
- Audio Electronics: Fundamentals of Circuits and Signals covers circuits, signal flow and studio infrastructure.
- Shaping Sound: Digital Audio, Signal Processing and Microphones applies it all to recording decisions.
Courses combine video lessons, readings, quizzes, exercises and discussions, with a teaching assistant and community forums for questions. Completion earns a certificate of completion and a digital badge, with lifetime access. Scheps calls it "a format where you do it at your own pace and you can go back."
Frequently asked questions
What are the basics of audio engineering?
The basics are how sound behaves (frequency, amplitude, wavelength and phase), how people hear it, how signals flow through gear and how levels are managed at each stage, and how digital audio, processing and microphones capture and shape sound. Once these are solid, every new tool becomes a variation on something you already understand.
Do you need math or physics to learn audio engineering?
You need basic arithmetic and a willingness to use a few formulas, not a physics degree. Relationships such as wavelength equals speed of sound divided by frequency, or +6 dB doubling amplitude, cover a lot of practical ground. The Core Audio Program asks students to have a calculator and a decibel measurement app, because the math is applied to real rooms and gear.
Is the Core Audio Program suitable for beginners?
Yes. The program is listed for all levels and requires no prior experience, building understanding from the ground up. It also helps experienced engineers fill gaps in self-taught knowledge, such as signal flow or impedance. Lessons open in sequence, so each concept is in place before the next one builds on it, and a teaching assistant answers questions.
Why learn how analog gear like the LA-2A works if you only use plugins?
Most plugins emulate analog designs or borrow their controls, so the same block diagram explains both. Knowing that an LA-2A's gain knob is just an output amplifier, or that transformers add noise, harmonic distortion and filtering, tells you what an emulation is trying to give you and which controls actually matter.
If you want to learn audio engineering online with the reasoning behind every tool, Andrew Scheps teaches all of this in the Core Audio Program. It is on-demand, built for all levels and backed by a 14-day money-back guarantee. You can also read what Campus students say on the reviews page.
