My audio has [describe problem: too quiet, noisy background, inconsistent levels, muddy sound].
Help me fix it using proper processing order.

Help me prepare this audio for [podcast/YouTube/Spotify/broadcast].
Current state: [describe audio]

Create an audio editing workflow for [content type].
Include settings for [software: Audacity/Audition/etc.]

## Correct Processing Order

1. GAIN STAGING
   ↓
2. NOISE REDUCTION
   ↓
3. COMPRESSION
   ↓
4. EQUALIZATION
   ↓
5. FINAL NORMALIZATION / LIMITING

Why this order:
- Noise reduction BEFORE compression: Prevents amplifying noise
- Compression BEFORE EQ: Prevents EQ changes affecting dynamics
- Limiting LAST: Sets final ceiling after all processing

## Gain Staging Guidelines

**Recording (target during capture)**:
- Peaks at -12 to -6 dB
- Leaves headroom for processing

**Initial Normalization (start of editing)**:
- Normalize peaks to -6 dB
- Creates consistent starting point

**Two Types of Normalization**:

1. **Peak Normalization**
   - Adjusts based on loudest point
   - Use for: Initial gain staging
   - Does NOT change dynamic range

2. **RMS/Loudness Normalization**
   - Adjusts based on average level
   - Use for: Final delivery
   - Better for perceived loudness matching

## Noise Reduction Approach

**When to use**:
- Consistent background hiss/hum
- Air conditioning, computer fan noise
- Not for variable noise (traffic, voices)

**Method 1: Spectral Noise Reduction**
1. Find 2-3 seconds of "silence" (noise only)
2. Use as noise profile
3. Apply reduction to full track
4. Use conservative settings

**Settings Guide** (Audacity example):
- Noise Reduction: 6-12 dB (start low)
- Sensitivity: 4-6 (higher = more aggressive)
- Frequency Smoothing: 3-6 bands

**Method 2: Noise Gate**
- Sets threshold; audio below is silenced
- Better for breaths between speech
- Doesn't affect audio during speech

**Warning Signs of Over-Processing**:
- "Underwater" or "robotic" sound
- Swirling artifacts
- Unnatural silence between words

**Rule**: If choosing between slight noise or artifacts, keep the noise.

## Compression for Voice

**What It Does**:
- Reduces volume of sounds above threshold
- Results in more consistent, fuller sound

**Key Parameters**:

| Parameter | What It Does | Voice Setting |
|-----------|--------------|---------------|
| Threshold | Level where compression starts | -20 to -12 dB |
| Ratio | How much to reduce | 2:1 to 4:1 |
| Attack | How fast compression kicks in | 10-30 ms |
| Release | How fast compression stops | 100-300 ms |
| Makeup Gain | Boosts output after compression | To taste |

**Voice Compression Starting Point**:
- Threshold: -18 dB
- Ratio: 3:1
- Attack: 15 ms (fast enough for transients)
- Release: 150 ms
- Gain: +3-6 dB (compensate for reduction)

**Multi-Band Compression** (advanced):
- Different settings for different frequency ranges
- Useful for controlling low-end rumble without affecting highs
- Overkill for most marketing audio

**When NOT to Compress**:
- Already consistent audio (well-recorded)
- Music meant to be dynamic
- Over-compression sounds "squashed"

## EQ for Voice

**Philosophy**: Cut more than boost. Removing problems is safer than adding "goodness."

**Voice Frequency Guide**:

| Range | Frequency | Effect |
|-------|-----------|--------|
| Rumble | Below 80 Hz | Cut (high-pass filter) |
| Muddiness | 200-400 Hz | Cut if boomy |
| Body/Warmth | 150-250 Hz | Boost slightly for thin voice |
| Boxy/Nasal | 400-800 Hz | Cut if honky |
| Clarity/Presence | 2-4 kHz | Boost for intelligibility |
| Sibilance | 5-8 kHz | Cut if harsh "s" sounds |
| Air/Brightness | 8-12 kHz | Boost for expensive studio feel |

**Standard Voice EQ Recipe**:
1. High-pass filter at 80 Hz (removes rumble)
2. Cut 2-3 dB around 300 Hz (reduces muddiness)
3. Boost 2-3 dB around 3 kHz (adds clarity)
4. High-shelf boost at 10 kHz if needed (adds air)

**De-essing**:
- Tames harsh "s" and "sh" sounds
- Target: 5-8 kHz range
- Use de-esser plugin OR narrow EQ cut

## Loudness Standards by Platform

| Platform | Target | Measurement |
|----------|--------|-------------|
| Podcast (general) | -16 LUFS | Integrated loudness |
| Spotify/Apple Podcasts | -14 LUFS | May normalize further |
| YouTube | -14 LUFS | Recommended |
| Broadcast TV (US) | -24 LKFS | FCC regulation |
| ACX/Audiobooks | -23 to -18 dB RMS | Per chapter |

**Final Steps**:

1. **Loudness Normalization**
   - Match to platform standard (e.g., -16 LUFS)
   - Use loudness meter, not peak meter

2. **Limiting**
   - Prevents clipping
   - Set ceiling at -1 dB (leaves headroom for encoding)
   - Catches peaks that exceed ceiling

3. **Export Settings**
   - Podcast: 128-192 kbps MP3, stereo
   - Video: Match video project settings
   - Audiobook: 192 kbps MP3, 44.1 kHz, mono

## Pre-Processing
□ Imported audio to project
□ Listened through once for problems
□ Noted specific issues (noise, pops, volume spikes)
□ Backed up original file

## Processing (in order)
□ 1. Gain staging: peaks at -6 dB
□ 2. Noise reduction applied (if needed)
□    - Used clean noise sample
□    - Checked for artifacts
□ 3. Compression applied
□    - Threshold set appropriately
□    - Gain reduction 3-6 dB typical
□ 4. EQ applied
□    - High-pass engaged
□    - Problem frequencies cut
□ 5. Final limiting
□    - Ceiling at -1 dB (or per platform)

## Quality Check
□ A/B comparison with bypass
□ Listened on headphones
□ Listened on different speakers
□ No artifacts or processing sounds
□ Loudness matches target spec

## Quick Reference: Delivery Specs

PODCASTS
- Loudness: -16 LUFS
- Format: 128-192 kbps MP3
- Channels: Mono or Stereo

YOUTUBE
- Loudness: -14 LUFS
- Format: Match video settings
- Note: Will be normalized by platform

AUDIOBOOKS (ACX)
- RMS: -23 to -18 dB
- Peak: -3 dB max
- Noise floor: -60 dB
- Format: 192 kbps MP3, 44.1 kHz, mono

BROADCAST (US)
- Loudness: -24 LKFS
- True peak: -2 dB
- Note: FCC regulated

MUSIC STREAMING
- Loudness: -14 LUFS (Spotify reference)
- Platforms normalize, but masters are louder

name: audio-editing
category: audio
subcategory: editing
version: 1.0
author: MKTG Skills
source_expert: iZotope, Industry Best Practices
source_work: Audio Engineering Standards
difficulty: beginner
estimated_value: $50-200 per hour (equivalent engineering time)
tags: [audio, editing, eq, compression, normalization, post-production]
created: 2026-01-26
updated: 2026-01-26