Lock Any Recording to a Fixed Grid

Intelligent Time Alignment for Variable-Tempo Music

Live recordings, old records, anything cut without a click — toggle Warp to Fixed BPM and Stemulator detects every beat and every harmonic change, then warps each one precisely into place on a fixed grid — even on songs with no drums. No warp markers. No tempo mapping. No DAW surgery.

Warp a Song Now See How It Works
Optional toggle · Beat-accurate · Pitch preserved
VARIABLE TEMPO FIXED BPM
The Problem

Why Recordings Drift from the Grid

Recordings made without a click track naturally vary in tempo — musicians push into choruses and settle through verses. That movement is part of the performance, but it is also what makes these recordings difficult to sample, remix, or play along with in a DAW.

A classic soul record can move between 92 and 97 BPM across three minutes. A live performance often lifts slightly in every chorus. A band demo follows the drummer. Import any of these into a DAW at a fixed tempo and the audio and the grid separate within a few bars — loops fall out of phase, MIDI stops lining up, and every edit requires manual correction.

The established solutions are manual. In Ableton Live, warp markers are placed and adjusted by hand. Logic's Smart Tempo generates a tempo map that must be reviewed and corrected bar by bar. Melodyne requires per-track beat assignment. Each approach is then repeated for every stem and verified by ear — significant preparation before any creative work begins.

How It Works

Beat-Accurate, Harmony-Aware Warping

This isn't a single average-tempo stretch. Enable Warp to Fixed BPM — or Warp to DAW Tempo in the plugin — and Stemulator corrects every beat individually, from subtle drift to outright tempo changes.

01

Map Every Beat & Harmonic Change

Stemulator places an exact marker on every performed beat — and detects every harmonic change via the chord map. Rhythmic and harmonic analysis together, not just drum transients.

02

Track the Drift

Most songs hold one tempo but drift around it — pushing here, settling there. Stemulator measures exactly how far every beat sits from the target grid.

03

Warp Every Beat Into Place

Each beat is time-stretched by precisely the amount it needs — no single-rate smear. And if a song genuinely changes tempo between sections, each section is warped at its own BPM.

04

Deliver Grid-Locked Stems

Up to 18 separated stems come back locked to a clean whole-number BPM, pitch untouched, ready to drop at bar 1 of any DAW project.

Because the warp is driven by the song's actual beat markers and its harmonic changes — not an averaged tempo guess, and not drum transients alone — it holds up across all kinds of music: live albums, 60s and 70s records, jazz rhythm sections, worship recordings, garage-band demos, even solo piano and acoustic ballads with no drums at all. And because it runs on every stem in the same pass, the stems stay sample-locked to each other.

Pair it with Crop to First Downbeat and the stems simply import grid-aligned: set your DAW's tempo to the stems' BPM, drop them at bar 1, and every beat is already on the grid — no nudging, no markers, nothing to fix.

PRE-ROLL BAR 1 ALIGNED
The Honest Comparison

Every Other Way to Do This Is Manual

DAWs can conform variable tempo, and we say so plainly. The difference is how much manual work each route requires.

Manual · In-DAW

Ableton Warp Markers

Enable warping, then place and adjust markers wherever the automatic transient analysis misreads the performance.

  • Marker-by-marker handwork
  • Per-clip: repeat for every stem
  • Accuracy depends on manual effort
Workflow · Manual, marker by marker
Semi-Automatic · In-DAW

Logic Smart Tempo / Melodyne

Analyze the file, receive a tempo map, then review it bar by bar and correct the places it lost the beat. Powerful — but still a manual verification pass, performed inside a DAW.

  • Tempo map requires correction by ear
  • Multitrack alignment is left to you
  • No stem separation involved
Workflow · Semi-automatic, corrected by ear
Automatic · Stemulator Only

Stemulator Warp

Upload the song, toggle Warp to Fixed BPM. Beat mapping, drift correction, and stem separation happen in one automatic pass — from a browser.

  • Zero markers, zero map editing
  • All stems warped together, sample-locked
  • Original pitch preserved
Workflow · One toggle, fully automatic
Head to Head

No Other Stem Separator Does This

Every other separation tool returns stems at the original song's drifting tempo — the tempo-mapping work is left to you.

FeatureStemulatorMoisesLALAL.AIFadr
Stem separation✓✓✓✓
Automatic time alignment (Warp to Fixed BPM)✓———
Multi-tempo support (each tempo section at its own BPM)✓———
Crop to First Downbeat✓———
DAW plugin warps stems to project tempo✓———

Competitor features verified against public feature pages, June 2026.

Built For

Who Needs Time Alignment

🎧
Remixers & Producers
Sample a 1972 groove at a locked 95 BPM. Layer modern drums under a live vocal. The grid finally cooperates.
🎚️
DJs
Tracks that used to be unmixable — live versions, older records — become set-ready, beatmatched, and loopable.
🥁
Musicians Practicing
Play along to a steady version of any song, or keep the original feel — your choice, same upload.
🎬
Editors & Post
Cut picture to music that holds tempo. Grid-locked stems make music editing predictable.
🎛️
DAW Plugin Users
The Stemulator plugin warps stems straight to your project's BPM and grid — variable tempos arrive fixed, inside the session.
📼
Archivists & Restorers
Give old recordings a modern, grid-stable release version without touching the pitch or the performance.
FAQ

Time Alignment Questions

How do I align a song with variable tempo to my DAW's grid?
Upload the song to Stemulator and enable the optional Warp to Fixed BPM setting. Stemulator detects every beat marker and harmonic change, then time-stretches the performance beat by beat to a fixed whole-number tempo — and if a song genuinely changes tempo between sections, each section is handled at its own BPM. The stems you download are already grid-aligned — no warp markers, no tempo mapping in your DAW.
Can this fix tempo drift in live recordings or old records made without a click track?
Yes — that's exactly what it's built for. Live recordings, old soul and funk records, band demos, anything cut without a click: Stemulator maps the actual performed beats and conforms them to a fixed grid while preserving the original pitch.
How is this different from Ableton warping, Logic Smart Tempo, or Melodyne?
DAWs can conform variable tempo, but it's a manual process: you place or correct warp markers, verify the tempo map bar by bar, and repeat for every track. Stemulator does it automatically — it warps every beat into place using exact beat markers and the harmonic changes in the song's chord map — so it works even where transient detection has nothing to grab — and it does it for all of your separated stems at once, in one pass, from a browser.
Does it work on songs without drums?
Yes. Stemulator's beat map is built from harmonic changes — the chord map — as well as rhythmic transients, so solo piano, acoustic guitar, choir, and other drumless recordings align just as accurately. Transient-based warping in a DAW has little to grab on material like this; harmonic analysis doesn't have that problem.
Is time alignment always applied?
No — it's an optional setting. Leave it off and your stems come back at the song's original tempo with the feel intact. Turn on Warp to Fixed BPM (or Warp to DAW Tempo in the DAW plugin) when you want everything locked to a fixed grid.
Does warping to a fixed BPM change the pitch?
No. Stemulator's warp pipeline time-stretches without changing pitch, so the song stays in its original key.
Do other stem separators offer variable-tempo warp?
No. As of mid-2026, no other stem separation platform offers automatic time alignment of variable-tempo music. Stems from other tools come back at the original song's drifting tempo, leaving the tempo-mapping work to you.
Which plans include Time Alignment?
The Audiophile plan includes Warp to Fixed BPM — the track is warped to its original tempo's nearest whole BPM. The Production plan adds Warp to DAW Tempo, which warps stems to your DAW project's tempo, and gives you the option to intelligently slow the track to twice the beats per bar when that makes more sense for remixing. Production also includes Time Alignment as a standalone workflow — time-align any track without separating it into stems, in the apps and the DAW plugin.
Does it work with my DAW?
Yes — the output is standard audio locked to a fixed whole-number BPM, so it drops onto the grid in Ableton Live, Logic Pro, FL Studio, Pro Tools, Cubase, Reaper, or any other DAW. Combined with Crop to First Downbeat, the stems simply import grid-aligned — set your DAW tempo to the stems' BPM and drop them at bar 1. The Stemulator DAW plugin goes further with Warp to DAW Tempo, which warps stems directly to your project's tempo and grid.

Stop Fighting the Grid

Upload one song that's never sat right in your DAW. Toggle Warp to Fixed BPM. Hear it land.

Try It On Your Track

Time Alignment is included with the Audiophile and Production plans.

Related Tools
Remix Production Suite Stem Separator DAW Plugin Musicians Mode

Download The App

Mac Windows iOS Android
Terms of Service Privacy Policy Data Deletion Contact