# Audio Sidechain Compress

Mix two tracks using sidechain compression (e.g., voice or ads audio when overlaying sidechain audio)

> Canonical page: https://elysiatools.com/en/tools/audio-sidechain-compress

- **Category:** Media

- **Keywords:** audio, sidechain, compress, ducking

## Overview

Audio Sidechain Compress is a tool that mixes two audio tracks using sidechain compression, allowing one audio to automatically reduce the volume of another. This is ideal for scenarios like voiceovers, podcasts, or ads where background music needs to duck when dialogue is present.

## Inputs

- **Main Audio** (file): Select the main audio (foreground)
- **Sidechain Audio** (file): Select the sidechain audio (e.g., voice)
- **Overlay Offset (seconds or hh:mm:ss\[.ms\])** (text): e.g., 5 or 00:00:05
- **Threshold (e.g., -20dB)** (text): -20dB
- **Ratio** (text): e.g., 4
- **Attack (ms)** (text): e.g., 20
- **Release (ms)** (text): e.g., 300
- **Output Format** (select)
- **Sample Rate** (select)
- **Audio Channels** (select)

## When to use

- When adding voiceover or narration to background music in videos or podcasts to ensure clarity.
- When overlaying advertisements or announcements on continuous audio tracks for better audibility.
- When creating dynamic audio mixes where one element should dominate over another at specific times, such as in live recordings or broadcasts.

## How it works

- Upload the main audio file, which is the foreground track like music or ambient sound.
- Upload the sidechain audio file, which triggers the compression, such as voice or ad audio.
- Adjust parameters like threshold, ratio, attack, and release to control how much and how quickly the main audio is reduced.
- Optionally set an offset to delay the sidechain effect, choose output format and sample rate, then process the mix.

## Use cases

- Podcast production: Mix host voice with background music to maintain listener engagement without manual adjustments.
- Video editing: Add voiceover to video audio tracks, ensuring dialogue is clear over background sounds.
- Audio advertising: Overlay ad clips on background music in radio or streaming content for effective messaging.

## Frequently asked questions

### What is sidechain compression?

Sidechain compression is an audio effect where the volume of one track is reduced based on the level of another track, commonly used for ducking effects like lowering music when voice is present.

### What audio formats can I upload?

You can upload any common audio format like MP3, WAV, AAC, etc., as the tool accepts audio/* files up to 200MB each.

### How do I set the overlay offset?

Enter the offset in seconds or hh:mm:ss[.ms] format to delay when the sidechain effect starts relative to the main audio, such as '5' for 5 seconds.

### What are the default compression settings?

Default settings are threshold -20dB, ratio 4, attack 20ms, and release 300ms, but you can customize them to suit your audio mix.

### Can I use this for live audio processing?

No, this tool processes uploaded audio files and is not designed for real-time or live audio; it outputs a mixed file for download.

## Related tools

- [Harshness Tamer](https://elysiatools.com/en/tools/audio-harshness-tamer): Detect and dynamically attenuate harshness in the 2–5 kHz presence band — a dynamic-EQ-style cut that only bites when the band actually plays loud.
- [Audio Podcast Intro/Outro Ducker](https://elysiatools.com/en/tools/audio-podcast-intro-outro-ducker): Automatically duck a music bed under voice/dialogue using sidechain compression, with fade-in/out templates for intros and outros.
- [Audio Deverb Lite](https://elysiatools.com/en/tools/audio-deverb-lite): Light de-reverb using EQ, compression, and denoise
- [Audio Metadata Compress](https://elysiatools.com/en/tools/audio-metadata-compress): Compress or remove metadata and embedded artwork to reduce file size
- [Audio Time Stretch](https://elysiatools.com/en/tools/audio-time-stretch): Stretch or compress audio to a target duration
- [Video Bitrate Changer](https://elysiatools.com/en/tools/video-bitrate-changer): Change video and audio bitrate with preset values or custom settings, supporting both CBR and VBR modes
- [WAV Compress](https://elysiatools.com/en/tools/wav-compress): Compress a WAV file by converting to MP3, AAC, OGG, or Opus
- [Audio Description Ducking](https://elysiatools.com/en/tools/audio-audio-description-ducking): Mix an audio-description narration into program audio while ducking the program when narration is present.

## Samples

- [Copyright-Free FLAC Audio Samples](https://elysiatools.com/en/samples/flac-samples): Lossless FLAC audio samples for testing and development, mirrored from MP3 set with nature sounds and meditation music
- [Copyright-Free MP3 Audio Samples](https://elysiatools.com/en/samples/mp3-samples): Collection of royalty-free audio samples for testing and development purposes including nature sounds, meditation music, and ambient audio
- [Copyright-Free WAV Audio Samples](https://elysiatools.com/en/samples/wav-samples): Uncompressed PCM WAV audio samples for testing and development, mirrored from MP3 set with nature sounds and meditation music
- [Copyright-Free Raw PCM Audio Samples](https://elysiatools.com/en/samples/pcm-samples): Raw PCM s16le audio samples featuring nature ambience and relaxing music for waveform, playback, and conversion workflows