Glossary

Core audio terms

Sampling

The process of representing a continuous signal as a sequence of time samples. Sampling rate defines how many samples per second are captured and processed.

Sample Rate

Number of samples per second, measured in Hz (for example 44.1 kHz, 48 kHz, 96 kHz). Maximum reproducible frequency is limited by half of sample rate (Nyquist theorem).

Quantization

Rounding each sample amplitude to the nearest digital level. It introduces quantization noise, reduced by higher bit depth.

Bit Depth

Number of bits per amplitude sample (16-bit, 24-bit, 32-bit float). It affects dynamic range and headroom.

Spectrum

Frequency-domain representation of a signal: which frequencies are present and with what amplitude.

Phase

Relative timing position of a waveform versus a reference. Phase differences can cause constructive or destructive frequency interaction.

Analysis and transforms

Fourier Transform

A mathematical transform from time domain to frequency domain. It reveals the frequency makeup of a signal.

Discrete Fourier Transform (DFT)

Computable Fourier form for finite discrete sequences. Widely used in digital audio processing.

Fast Fourier Transform (FFT)

An efficient algorithm for DFT computation. Core tool for real-time spectral analysis.

Z-Transform

Representation of discrete systems in the complex Z-domain. Used for stability analysis and digital filter design.

Filters and characteristics

Digital Filter

An algorithm that shapes the frequency content of a signal. Can be FIR or IIR, low-pass, high-pass, band-pass, and more.

Frequency Response Magnitude

Amplitude change versus frequency for a system. Shows how much each frequency is boosted or attenuated.

Phase Response

Phase shift versus frequency for a system. Important for transient behavior and multi-path alignment.

Transfer Characteristic

Input/output relationship of a system. For nonlinear stages (for example distortion), it defines saturation and harmonic generation behavior.

Volt-Ampere Characteristic (I-V Curve)

Current-voltage relationship of an electronic element. In guitar modeling, it helps describe nonlinear analog stages.

Dynamics and envelopes

ADSR Envelope

Amplitude-over-time model with Attack, Decay, Sustain, and Release segments. Common in synthesis and dynamic modulation.

Threshold

Level at which a dynamics processor starts acting (for example gate or compressor).

Attack Time

How quickly a processor reacts when signal exceeds threshold.

Release Time

How quickly a processor returns to idle after signal drops below threshold.

Electric guitar signal chain

DI Signal

Clean instrument signal before amp and cabinet coloration. Commonly used for reamping.

Reamping

Reprocessing a previously recorded DI signal through a different processing chain or amplifier setup.

Noise Gate

A dynamics processor that closes at low levels to reduce noise.

Amp

Core tone-shaping stage of guitar sound: affects dynamics, harmonics, and distortion character.

Cabinet (Cab / IR)

Acoustic response of a guitar cabinet and microphone path. Typically modeled via impulse response (IR).

Impulse Response (IR)

System response to a short impulse. Enables linear modeling of cabinets, reverberation spaces, and other acoustic systems.

Equalizer (EQ)

A tool for boosting or attenuating selected frequency ranges.

Clipping

Peak limiting when signal exceeds maximum representable level. It can be either an unwanted artifact (digital clipping) or a creative effect.