RIM 3 nbtea

Signal Processing

A cornerstone of modern audio engineering, offering techniques and tools to manipulate sound.

Dynamic Range

Difference between the loudest and quietest moments in an audio source.

Compression

Reduces output level as input level increases, managing loud parts in a performance.

Threshold (Compression)

The input level at which compression starts.

Ratio (Compression)

The amount of gain reduction applied once the threshold is exceeded; higher ratios result in more compression.

Limiting

A form of compression with a high ratio (typically 10:1 or greater) to prevent the output level from exceeding a set threshold.

Ceiling (Limiting)

The maximum output level that is capped by limiting.

Expansion

Reduces gain as input levels drop, making quiet sounds quieter.

Threshold (Expansion)

Level below which expansion begins.

Ratio (Expansion)

Defines how much the signal is attenuated; ratios of 10:1 or greater are categorized as gating.

Gating

Effectively eliminates unwanted sounds like drum resonance or tape hiss in analog recordings.

Side Chain Processing

Incorporates an external input to trigger processing, useful in applications like de-essing or ducking.

De-Essing

Targets sibilant frequencies in vocals to reduce harsh 's' sounds.

Ducking

Used in broadcasting and electronic dance music to lower the volume of certain elements dynamically.

Equalization (EQ)

Allows specific frequency ranges to be boosted or cut, helping to shape the tonal balance of audio sources.

Applications of Compression

Reducing wide dynamic ranges, useful for amateur singers or instruments prone to volume spikes.

Applications of Expansion

Increasing small dynamic ranges, appropriate for reducing background noise from amplifiers without affecting the main performance.

Controls of Gating

Useful for noise removal.

Advanced Editing Features

Less necessary in digital recording due to inherent lower noise levels.

Spectral Balance

Focuses on the tonal balance of audio sources.

Low-Pass/High-Cut

Removes frequencies above the cutoff point.

High-Pass/Low-Cut

Removes frequencies below the cutoff point.

Band-Pass

Allows frequencies within a specific range to pass through while attenuating frequencies outside this range.

Notch Filter

Attenuates a narrow band of frequencies.

Shelving EQ

Boosts or cuts frequencies above or below a certain point and then flattens out.

Peaking (Parametric) EQ

Can boost or cut a specific frequency range, with controls for the amount of boost/cut, center frequency, and bandwidth (Q factor).

Phase Shift

Timing variations between different frequencies caused by equalization.

Impact of Phase Shift

The amount of phase shift depends on filter design, amount of boost/cut, filter slope, and bandwidth.

Reverb

Simulates the sound of reflections in a physical space, adding depth and richness to audio.

Types of Reverb

Different types include spring reverb, plate reverb, and digital reverberation.

Delay

Creates an echo effect by repeating the audio signal after a short period.

Types of Delay

Tape delays and digital delays are common types.

Phasing

Uses phase shift filters to create frequency notches and add movement to sounds.

Flanging

Combines a delayed signal with the original to produce a comb filter effect, creating sweeping sounds.

Chorus

Simulates multiple performers by slightly varying pitch and timing.

Automatic Double Tracking (ADT)

Uses slight variations in pitch and time to create a doubled recording effect.

Pitch Shifting

Changes the pitch of a recording without altering the tempo.

Early Methods of Pitch Shifting

Involved tape speed variations, but modern techniques use digital algorithms for more precise control.

Pitch Correction

Software tools like AutoTune and Melodyne can correct the intonation of performances, making it possible to adjust pitch without affecting the overall sound quality.

Analog Consoles

Handle audio as an electrical signal.

Digital Consoles

Process audio as digital signals.

DAW (Digital Audio Workstation)

Computer-based mixing with software control surfaces for tactile adjustments.

Input and Output

Consoles are defined by their I/O capabilities, often denoted in formats like '32 x 24 x 2' (32 inputs, 24 groups, 2 program outputs).

Block Diagrams

Essential for understanding how signals move through a console. Signal paths are usually illustrated from input to output, showing processing blocks and routing flexibility.

Channel Strip

Individual channel modules in a console that contain preamps, EQ, dynamics, and routing controls.

Auxiliary Sends

Routes audio to external effects or monitor mixes, which can be pre- or post-fader.

Patch Bay

Central hub for routing signals within and outside the console, allowing flexibility in signal flow.

Automation

Systems that capture and playback console changes over time, synchronized with timecode for precision in editing.

Solo Modes

Allow isolation and monitoring of individual channels, differing in whether they monitor pre- or post-fader signals.

Talkback System

Facilitates communication between the control room and talent during recording sessions.

Impedance (Z)

A measure of opposition that a circuit presents to a current when a voltage is applied.

Ohms (Ω)

The unit of measurement for electrical resistance.

DI Box (Direct Box)

A device used to connect high-impedance instrument signals to low-impedance microphone inputs.

XLR Microphone Connector

A type of electrical connector used for balanced audio signals.

¼ Inch Phone Plug - TS (Unbalanced)

A type of audio connector used for unbalanced mono signals.

¼ Inch Phone Plug - TRS (Balanced)

A type of audio connector used for balanced mono or unbalanced stereo signals.

Bantam or TT (Tiny-Telephone) Plug

A smaller version of the ¼ inch phone plug, used for patch bays.

3.5mm (1/8") Mini Plug

A common audio connector used for headphones and portable devices.

RCA Connector

A type of electrical connector commonly used for audio and video signals.

Speakon® Connector

A type of connector used for loudspeakers, designed to prevent accidental disconnection.

Channel Fader

A control used to adjust the volume level of an individual audio channel.

Master Fader

A control used to adjust the overall output level of a mixer or console.

Phantom Power (48V)

A method of providing power to condenser microphones through the microphone cable.

Compressor vs. Limiter

A compressor reduces the dynamic range of audio, while a limiter prevents audio from exceeding a certain level.

RT60 - Decay Time

The time it takes for sound to decay by 60 decibels in a given space.

Reverberation

The persistence of sound in a space after the original sound has stopped.