--- name: audio-production description: Professional audio production for music, podcasts, and sound design. Use when working with audio recording, mixing, mastering, or sound design for any medium. --- # Audio Production Comprehensive guide for professional audio production across music, podcasts, video, and interactive media. ## Audio Fundamentals ### The Audio Signal Chain ``` SOURCE → CAPTURE → PROCESS → OUTPUT Detailed: ┌─────────┐ ┌─────────┐ ┌─────────┐ ┌─────────┐ │ Source │→→→│ Mic │→→→│ Preamp │→→→│Interface│ │(voice, │ │ │ │ │ │ (A/D) │ │ instr.) │ │ │ │ │ │ │ └─────────┘ └─────────┘ └─────────┘ └────┬────┘ │ ▼ ┌─────────┐ ┌─────────┐ ┌─────────┐ ┌─────────┐ │Speakers │←←←│ (D/A) │←←←│ Mix │←←←│ DAW │ │Headphone│ │Interface│ │ Master │ │Recording│ └─────────┘ └─────────┘ └─────────┘ └─────────┘ ``` ### Key Audio Concepts | Concept | Definition | Standard | |---------|------------|----------| | **Sample Rate** | Samples per second | 44.1kHz, 48kHz, 96kHz | | **Bit Depth** | Dynamic range resolution | 16-bit, 24-bit, 32-bit float | | **Bit Rate** | Data per second (compressed) | 128-320 kbps (MP3) | | **Dynamic Range** | Loudest to quietest | ~96dB (16-bit), ~144dB (24-bit) | | **Headroom** | Space below 0 dBFS | -6 to -18 dB typical | ### Frequency Spectrum ``` 20 Hz 20,000 Hz ├───────────────────────────────────────────────────────┤ SUB-BASS │ BASS │ LOW-MID │ MID │ HIGH-MID │ HIGH 20-60 │ 60-250 │ 250-500 │500-2k │ 2k-6k │ 6k-20k │ │ │ │ │ Rumble │ Warmth │ Body │ Pres- │ Presence │ Air Feel │ Punch │ Muddiness│ ence │ Harshness│ Sibilance ``` ### Decibel Reference Points ``` dBFS (Full Scale): 0 dBFS ████████████ Digital maximum (clipping) -3 dBFS ██████████ Peaks (leave headroom) -6 dBFS █████████ Recommended peak ceiling -12 dBFS ███████ Average loud signal -18 dBFS ██████ Recommended recording level -24 dBFS ████ Conservative level -60 dBFS █ Noise floor target ``` --- ## Recording ### Microphone Types | Type | Principle | Best For | |------|-----------|----------| | **Dynamic** | Moving coil | Loud sources, live, durable | | **Condenser** | Capacitor | Studio vocals, acoustic, detail | | **Ribbon** | Thin metal strip | Vintage tone, smooth highs | | **USB** | Built-in ADC | Podcasts, convenience | ### Polar Patterns ``` CARDIOID FIGURE-8 OMNI ╭─────╮ ╭───╮ ╭─────╮ ╭─┤ ├─╮ ╭─┤ ├─╮ ╭─┤ ├─╮ │ │ │ │ │ │ │ │ │ │ │ │ │ │ ● │ │ │ │ ● │ │ │ │ ● │ │ │ │ │ │ │ │ │ │ │ │ │ │ ╰─┤ ├─╯ ╰─┤ ├─╯ ╰─┤ ├─╯ ╰─────╯ ╰───╯ ╰─────╯ Front pickup Front + Back All around ``` ### Recording Levels ``` Target Peaks: -12 to -6 dBFS Average Level: -18 to -12 dBFS Why? - Leaves headroom for processing - Matches analog equipment sweet spot - Prevents digital clipping - 24-bit has plenty of resolution ``` ### Recording Best Practices - [ ] Set gain before recording (never during) - [ ] Record at 24-bit minimum - [ ] Use 48kHz for video, 44.1kHz for music - [ ] Monitor with headphones - [ ] Record a few seconds of room tone - [ ] Check phase when using multiple mics - [ ] Label takes immediately --- ## Essential Processing ### EQ (Equalization) ``` Types: - High-pass filter (HPF): Removes low frequencies - Low-pass filter (LPF): Removes high frequencies - Bell/Peak: Boost or cut specific frequency - Shelf: Boost or cut above/below frequency Common Applications: ┌─────────────────────────────────────────┐ │ Vocal: │ │ HPF at 80-100Hz (remove rumble) │ │ Cut 200-300Hz (reduce mud) │ │ Boost 3-5kHz (presence) │ │ Shelf boost 10kHz+ (air) │ ├─────────────────────────────────────────┤ │ Kick Drum: │ │ Boost 50-80Hz (sub) │ │ Cut 300-400Hz (boxiness) │ │ Boost 3-5kHz (attack/click) │ ├─────────────────────────────────────────┤ │ Electric Guitar: │ │ HPF at 80Hz │ │ Cut 400-600Hz if muddy │ │ Boost 2-4kHz (bite) │ └─────────────────────────────────────────┘ ``` ### Compression ``` Parameters: ┌────────────────────────────────────────────────┐ │ Threshold: Level where compression starts │ │ Ratio: Amount of compression (4:1, 8:1, etc.) │ │ Attack: Time to engage (fast=punch, slow=body)│ │ Release: Time to disengage │ │ Knee: Hard (sudden) or soft (gradual) │ │ Makeup Gain: Restore lost volume │ └────────────────────────────────────────────────┘ Common Settings: ┌─────────────────────────────────────────┐ │ Vocals: 3:1-4:1, medium attack/release │ │ Drums: 4:1-8:1, fast attack │ │ Bass: 4:1, medium attack │ │ Mix Bus: 2:1-3:1, slow attack, 1-3dB GR│ └─────────────────────────────────────────┘ ``` ### Reverb | Type | Character | Use | |------|-----------|-----| | **Room** | Small, tight | Natural ambience | | **Hall** | Large, spacious | Orchestral, ballads | | **Plate** | Bright, smooth | Vocals, snare | | **Spring** | Vintage, boingy | Guitar, lo-fi | | **Chamber** | Warm, dense | Natural depth | ``` Key Parameters: - Pre-delay: Time before reverb (50-100ms for vocals) - Decay/RT60: How long it lasts - Damping: High-frequency absorption - Size: Room dimensions - Mix/Wet-Dry: Balance with original ``` ### Delay | Type | Application | |------|-------------| | **Slapback** | 50-150ms, rockabilly, presence | | **Stereo** | Different L/R times, width | | **Ping-pong** | Alternating L/R, interest | | **Tempo-sync** | 1/4, 1/8 notes, rhythmic | --- ## Mixing ### Gain Staging ``` Signal Flow Levels: ┌─────────────────────────────────────────┐ │ Input: -18 dBFS (sweet spot) │ │ ↓ │ │ Plugin 1: Output matches input level │ │ ↓ │ │ Plugin 2: Output matches input level │ │ ↓ │ │ Fader: Unity (0 dB) ideally │ │ ↓ │ │ Bus: -12 to -6 dBFS peaks │ │ ↓ │ │ Master: -6 dBFS peaks (before limit) │ └─────────────────────────────────────────┘ ``` ### Panning Guidelines ``` Stereo Field: Hard L L L-C CENTER R-C R Hard R │ │ │ │ │ │ │ │ │ │ │ │ │ │ Rhythm Gtr1 Keys1 Vocal Keys2 Gtr2 Rhythm Gtr BVox1 Bass BVox2 Gtr Kick Snare Common Positions: - Center (0): Lead vocal, bass, kick, snare - Slight L/R: Main instruments, harmonies - Wide L/R: Rhythm guitars, stereo keys - Hard L/R: Doubled parts, effects ``` ### Frequency Balancing ``` Making space (subtractive EQ approach): ┌────────────────────────────────────────────┐ │ Kick: Boost 60Hz │ Cut from Bass here │ │ Bass: Boost 80-100 │ Cut from Kick here │ │ Gtr: Owns 1-3kHz │ Cut vocal slightly │ │ Vocal: Boost 3-5kHz │ Cut guitar slightly │ └────────────────────────────────────────────┘ Each element should have its own frequency "home" ``` ### Mix Bus Processing ``` Typical Chain: 1. Subtle EQ (tonal shaping) 2. Light compression (2:1, 1-3dB GR) 3. Stereo enhancement (if needed) 4. Limiter (only for reference bounce) Keep mix bus processing minimal! Leave headroom for mastering. ``` --- ## Mastering ### Mastering Goals 1. **Tonal Balance**: Even frequency response 2. **Dynamics**: Appropriate loudness/dynamics 3. **Stereo Image**: Width and mono compatibility 4. **Translation**: Sounds good everywhere 5. **Format**: Prepare for distribution ### Loudness Standards | Platform | Target | Measurement | |----------|--------|-------------| | **Spotify** | -14 LUFS | Integrated | | **Apple Music** | -16 LUFS | Integrated | | **YouTube** | -14 LUFS | Integrated | | **Broadcast (US)** | -24 LUFS | Integrated | | **Broadcast (EU)** | -23 LUFS | Integrated | | **CD** | -9 to -12 LUFS | Integrated | ### Mastering Chain (Typical) ``` 1. Reference Import └─→ Compare to commercial releases 2. EQ (Linear Phase) └─→ Broad adjustments only 3. Multiband Compression └─→ Control specific bands 4. Stereo Width └─→ Enhance or narrow 5. Limiting └─→ Final loudness, prevent clipping 6. Dither (if needed) └─→ 16-bit conversion only ``` --- ## Podcast Production ### Recording Setup ``` Recommended Signal Chain: Mic → Audio Interface → DAW Equipment Tiers: ┌─────────────────────────────────────────┐ │ Budget: USB Mic (Blue Yeti, AT2020) │ │ Mid: SM7B + Cloudlifter + Interface│ │ Pro: Large diaphragm condenser │ │ + high-end preamp │ └─────────────────────────────────────────┘ ``` ### Podcast Processing Chain ``` 1. Noise Reduction └─→ Remove room noise, hum 2. De-essing └─→ Tame harsh "s" sounds 3. Compression └─→ Even out volume (3:1-4:1) 4. EQ └─→ HPF at 80Hz, presence boost 5. Limiter └─→ Catch peaks, -1 dBFS ceiling Target: -16 LUFS (mono), -19 LUFS (stereo) True Peak: -1 dBTP ``` ### Podcast Export Settings ``` Standard: - Format: MP3 or AAC - Bitrate: 128 kbps (mono), 192 kbps (stereo) - Sample rate: 44.1 kHz High Quality: - Format: AAC - Bitrate: 256 kbps - Sample rate: 48 kHz Chapters: Use ID3 tags for chapter markers Artwork: 3000x3000 minimum, JPG or PNG ``` --- ## Sound Design ### Creating Sounds ``` Approaches: 1. Recording: Capture real sounds (foley) 2. Synthesis: Create from oscillators 3. Sampling: Manipulate existing sounds 4. Processing: Transform through effects 5. Layering: Combine multiple sources ``` ### Synthesis Types | Type | Method | Sound Character | |------|--------|-----------------| | **Subtractive** | Filter oscillators | Classic analog | | **FM** | Frequency modulation | Metallic, bells | | **Wavetable** | Morphing waveforms | Modern, evolving | | **Granular** | Tiny sound particles | Texture, pads | | **Additive** | Stack sine waves | Precise, organs | | **Physical Modeling** | Simulate physics | Realistic instruments | ### Layering Formula ``` Sound Design Stack: ┌─────────────────────────────────────┐ │ TOP: High frequencies (air, presence)│ │ MID: Character, tone │ │ LOW: Foundation, weight │ │ SUB: Felt, not heard (20-60Hz) │ │ TRANSIENT: Attack, punch │ └─────────────────────────────────────┘ Process each layer separately, combine at end. ``` --- ## DAWs (Digital Audio Workstations) | DAW | Strengths | Platform | |-----|-----------|----------| | **Pro Tools** | Industry standard, editing | All | | **Logic Pro** | Complete package, Apple | macOS | | **Ableton Live** | Live performance, electronic | All | | **FL Studio** | Beat making, workflow | All | | **Reaper** | Customizable, affordable | All | | **Cubase** | MIDI, composition | All | | **Studio One** | Modern workflow | All | | **Audacity** | Free, simple editing | All | --- ## File Formats | Format | Type | Quality | Use | |--------|------|---------|-----| | **WAV** | Uncompressed | Lossless | Production, archive | | **AIFF** | Uncompressed | Lossless | Mac production | | **FLAC** | Compressed | Lossless | Archive, audiophile | | **ALAC** | Compressed | Lossless | Apple ecosystem | | **MP3** | Compressed | Lossy | Distribution | | **AAC** | Compressed | Lossy | Streaming, Apple | | **OGG** | Compressed | Lossy | Games, open source | ### Export Specifications ``` For Mastering: - Format: WAV - Bit depth: 24-bit (or 32-bit float) - Sample rate: Match session (typically 44.1/48kHz) - Headroom: -6 dBFS peaks For Distribution: - Format: WAV or FLAC (lossless) - Bit depth: 16-bit (with dither) - Sample rate: 44.1 kHz - Loudness: Platform target LUFS ``` --- ## Best Practices ### DO: - Record at proper levels (-18 dBFS average) - Use reference tracks - Take breaks (ear fatigue is real) - Check mono compatibility - Use subtractive EQ first - Process in series, not parallel (usually) - Save project versions regularly - Export stems for backup ### DON'T: - Record with processing (usually) - Mix at high volumes - Over-compress everything - Solo instruments too long - Trust only one playback system - Rush the mixing process - Forget to dither (16-bit only) - Master your own mixes (ideally) --- ## Quality Checklist ### Pre-Export - [ ] Gain staging correct throughout - [ ] No clipping or distortion - [ ] Phase issues resolved - [ ] Mono compatibility checked - [ ] Low-end translation verified - [ ] High frequencies not harsh ### Final Check - [ ] Listen on multiple systems - [ ] Check in car, phone, earbuds - [ ] Verify format specifications - [ ] Confirm LUFS target met - [ ] True peak below -1 dBTP - [ ] Metadata correctly embedded