Time Stretching: From Akai to Jungle Stretch

Time stretching – the ability to change the tempo of an audio clip without changing its pitch – is one of the most transformative technologies in modern music production. This article explores the history, technology, and tools that made it possible.

What is time stretching?

Time stretching (or tempo manipulation) is a digital audio processing technique that allows you to change the duration of an audio file. Used alone, you can lengthen or shorten a sample – turn a 2-second break into 4 seconds, or compress an 8-bar loop to half its length.

The real power comes when you combine time stretching with re-pitching (transposition). Traditionally, tempo and pitch were inextricably linked: Play a vinyl record faster, and everything goes up in pitch. With modern technology, you can:

• Change tempo without affecting pitch – perfect for matching breaks to your track
• Change pitch without affecting tempo – pitch a vocal up without making it faster
• Change both independently – the ultimate creative freedom

This independence between tempo and tone revolutionized music production and opened up creative possibilities that were unthinkable in the analog era.

The pioneers: Eventide and early effects processors

The history of digital pitch manipulation begins in the 1970s. Eventide introduced the H910 Harmonizer in 1975 – the world's first digital pitch shifter. It was a primitive start, but it demonstrated the potential of digital audio processing.

In 1986 came the Eventide H3000 Ultra-Harmonizer, which Brian Eno called the best effects unit ever. It could not only pitch-shift but offered complex sound manipulation used by producers from U2 to Depeche Mode. The H3000 laid the foundation for many of the algorithms we still use today.

Akai S950: The sound of jungle

If there's one machine that defined the jungle sound, it's the Akai S950 sampler (1988). With its 12-bit resolution and characteristic "crunchy" sound, it became an indispensable tool for early jungle producers.

When jungle producers stretched a breakbeat from 120 BPM to 160+ BPM, they didn't just get a faster break – they got an entirely new texture. The granular artifacts added grittiness and character that made the sound unique.

UK Jungle pioneers

The time stretching technique was essential for the wave of producers who shaped jungle and drum & bass in early 90s UK:

• Goldie (Metalheadz) – With the legendary "Timeless" (1995), he pushed the boundaries of what the genre could contain. His use of timestretched vocals and complex breakbeat manipulations set new standards.
• 4hero – Their "Parallel Universe" (1994) showed how the S950's time stretch could create almost orchestral textures from simple breaks.
  Hear the time stretch effect on the drums

  31:31 / 0:00

  Listen to the full album
• LTJ Bukem – Pioneer of atmospheric/liquid jungle, where stretched pads and breaks created dreamy soundscapes.
• Shy FX – The man behind "Original Nuttah" (1994) and master of the hard, ragga-inspired jungle sound with aggressive timestretched breaks.
  Original Nuttah – hear the timestretched breaks

  0:58 / 3:17

  Watch on YouTube

Tracks like Origin Unknown's "Valley of the Shadows" (1993) and 4hero's "Journey From The Light" (1991) showed how timestretching and pitchshifting could transform a simple breakbeat into something completely new and alien.

Modern jungle aesthetics

The jungle sound is alive and well in modern production. Two artists who deserve special attention:

• Special Request (Paul Woolford) – The Leeds producer has since 2012 created a bridge between rave nostalgia and modern club music. His project is directly inspired by UK's pirate radio era and uses timestretched breaks and vocals as signature elements.
• Pete Cannon – The Blackpool artist is one of the most dedicated advocates for authentic jungle production. He still uses Akai samplers, Ataris, and Amigas, and his tutorials on Sound On Sound are invaluable for anyone wanting to understand the original production techniques.

Akaizer: Legend in software form

For producers who wanted to recreate the S950's distinctive sound but didn't have access to vintage hardware, Akaizer came as a gift. This free Windows program, developed by an enthusiastic programmer, emulates exactly the algorithm Akai used.

Akaizer is simple: load a WAV file, select how many semitones you want to transpose, and save the result. It's deliberately minimalist – 100% focused on recreating the authentic sound.

The problem with Akaizer? It's Windows-only, requires installation, and the interface is... dated. For modern producers, it can feel like wrestling with technology from another era.

Ableton Live's Warp Engine

When Ableton Live launched in 2001, it revolutionized working with tempo and timing. The Warp function made it possible to synchronize any audio clip to the session's tempo in real-time – something that previously required hours of manual work.

Ableton offers several warp modes, each optimized for different sound types:

• Beats: Ideal for drums and percussion – keeps transients sharp
• Tones: For monophonic instruments and vocals
• Texture: For complex, atmospheric sounds
• Re-Pitch: Changes tempo by changing pitch (like a vinyl record)
• Complex/Complex Pro: For polyphonic mixes and master tracks

For most producers, Ableton's warp engine is all they need. But there's a problem: it's designed to sound transparent and neutral. If you want that characteristic jungle sound, you need to look elsewhere.

Jungle Stretch: Akaizer in the browser

Jungle Stretch solves all the problems that make Akaizer difficult to access:

• Runs in the browser – no installation, works on Mac, Windows, Linux, iPad
• Modern interface with real-time waveform display
• Tap tempo for quick BPM detection
• Sample rate reduction and bit crushing for authentic lo-fi sound
• Presets to save and recall settings
• Loop selection with precise control over your sample

Freesound integration: A unique feature

Time Stretch parameters

Jungle Stretch gives you full control over the parameters that define the sound:

Lo-Fi Processing (S950 Emulation)

To recreate the authentic S950 sound, Jungle Stretch includes lo-fi processing:

• Bit Depth: From 16-bit down to 4-bit for extreme quantization noise
• Sample Rate Reduction: From 44.1kHz down to 5.5kHz for classic aliasing
• Akai Filter: Low-pass filter emulating the S950's analog output stage

Time stretching in modern production

Today, time stretching is ubiquitous. Every DAW has it built in, and algorithms have become so advanced they can handle complex mixes almost transparently. But the creative use of "bad" time stretching – the artifacts and glitches the S950 created – lives on as a deliberate aesthetic choice.

Remember: Time stretching alone only changes duration. It's only when you combine it with transposition that you get the full creative palette – the ability to change tempo and pitch as two independent dimensions.

Try it yourself

Want to experiment with time stretching? Here's your quick start guide:

1. Find a break: Start with a simple drum loop. Read our article about jungle breaks for inspiration – or use Jungle Stretch's Freesound integration to fetch a random break.
2. Open Jungle Stretch: Go to junglestretch.com and load your file or click "Random Break".
3. Experiment: Try +12 semitones for classic jungle pitch, or -12 for sludgy drum & bass.
4. Add crunch: Enable lo-fi processing for authentic 90s character.
5. Download and use: Import the result into your DAW and build from there.

Additional resources

• Jungle Stretch – Akaizer in the browser (free)
• Freesound.org – Free sample library
• Reverb: The Samplers and Breakbeats Behind '90s Jungle/Drum & Bass
• Sound On Sound: Pete Cannon – Retro Jungle Production Techniques
• Voltage Control: The Long and Crunchy Life of the Akai S950

Om forfatteren

Ras 'Kata' Kjærbo

Ras Kjærbo is an Ableton Certified Trainer and one of the driving forces behind Rumkraft. He teaches Ableton Live and music production, and is passionate about sharing his knowledge on everything from sound design to live performance techniques.

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