# Audio Kick-Bass Phase Aligner

Compare kick and bass timing/phase in the low band, report the offset and polarity, and export the corrected track with sample-accurate alignment.

> Canonical page: https://elysiatools.com/en/tools/audio-kick-bass-phase-aligner

- **Category:** Media

- **Keywords:** kick bass, phase alignment, polarity, cross-correlation, low end, phase cancellation, transient alignment, mixing

## Overview

A low-end alignment assistant for separate kick and bass stems. Both tracks are decoded to PCM, low-passed (4th-order biquad cascade, default 120 Hz), and scanned with a normalized cross-correlation over a configurable ±ms window — the same "nudge until the correlation peaks" workflow engineers do by eye on an oscilloscope. The tool reports the inter-track offset in samples and milliseconds, whether polarity inversion improves the sum, the residual phase angle at the dominant low frequency (a 5 ms offset is 90° at 50 Hz), and how much combined low-end energy the fix recovers. The chosen track is then shifted sample-accurately (and polarity-flipped when recommended), and exported in your format with a post-fix correlation check. Perfectly aligned, in-polarity kick and bass sum coherently; offset or anti-phase pairs cancel audibly.

## Inputs

- **Kick track file** (file)
- **Bass track file** (file)
- **Track to adjust** (select)
- **Apply polarity fix** (checkbox)
- **Search range (± ms)** (number)
- **Analysis low-pass (Hz)** (number)
- **Output format** (select)

## When to use

- Kick and bass sum together weakly or lose low-end punch when played simultaneously.
- Acoustic drum recordings or bass guitar tracks have small transient timing discrepancies.
- Kick and bass stems suffer from anti-phase cancellation in the sub-bass frequency band.

## How it works

- Upload your kick and bass audio tracks and designate which stem should be shifted.
- A 4th-order biquad low-pass filter isolates low frequencies below the chosen cutoff frequency.
- Normalized cross-correlation scans the low-end waveforms across the search window to calculate offset and polarity alignment.
- The target stem is shifted sample-accurately, flipped in polarity if needed, and exported in your selected audio format.

## Use cases

- Mixing electronic music where sub-bass and kick drums must sum coherently for maximum impact.
- Aligning live-recorded electric bass tracks with acoustic kick drum microphones.
- Pre-processing audio stems before bus compression and final mastering.

## Frequently asked questions

### How does the tool calculate the optimal alignment?

It low-passes both tracks to isolate the low end and performs normalized cross-correlation over a configurable search window to find the peak correlation offset.

### Which track should I select as the adjustment target?

Shift the bass stem to keep the kick locked to your project grid, or shift the kick stem if the bass line is your primary timing reference.

### What does the polarity fix option do?

It tests whether inverting the target track's polarity improves coherent low-frequency summation and applies the flip if beneficial.

### How do I choose the search range in milliseconds?

The default 20 ms window handles most standard timing variations; use smaller ranges for tight electronic tracks or larger windows for loose live performances.

### Which export formats are supported?

You can export the corrected stem as WAV, FLAC, MP3, M4A, or OGG Vorbis.

## Related tools

- [Audio Bass Boost](https://elysiatools.com/en/tools/audio-bass-boost): Boost the low-frequency (bass) sounds
- [Audio Groove Quantizer](https://elysiatools.com/en/tools/audio-groove-quantize): Detect loop transients and pull them toward a beat grid, swing template, or a reference audio groove.
- [Audio Phase Fix](https://elysiatools.com/en/tools/audio-phase-fix): Fix phase and stereo width issues
- [Audio Speaker Turn Detector](https://elysiatools.com/en/tools/audio-speaker-turn-detector): Mark likely acoustic turn changes in speech-range audio and export an approximate turn timeline.
- [Audio Wow Flutter Corrector](https://elysiatools.com/en/tools/audio-wow-flutter-corrector): Reduce mild tape speed wobble and compensate known speed offset in audio recordings.
- [Video Audio Replace](https://elysiatools.com/en/tools/video-audio-replace): Replace the audio track in a video file with a new audio file while keeping the original video
- [Audio Podcast Loudness Compliance Report](https://elysiatools.com/en/tools/audio-podcast-loudness-compliance-report): Compare integrated LUFS, true peak, LRA, stereo/mono, bitrate and sample rate against Apple Podcasts, Spotify, YouTube, ACX and broadcast targets.
- [Audio Silence Detector](https://elysiatools.com/en/tools/audio-silence-detector): Detect and list the start and end times of silent parts

## 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