Beat Kitchen Harmonic Synth vs HeadStack
Price, ratings, monetisation and update history for both apps, side by side — with what reviewers say about each.
Beat Kitchen Harmonic Synth
Shape the overtone series directly to create unique sounds. This additive synthesizer allows real-time manipulation of harmonics, LFOs, and envelopes. Explore sound design and synthesis on your device.
- Additive synthesis engine
- Overtone series shaping
- Live waveform and spectrum response
- Modulation matrix with LFOs and envelopes
- AUv3 support
- On-device processing
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BKS Harmonic is an additive synthesizer that builds sound from individual overtones, then gives you tools to shape, scan and filter them by harmony. Load it as an Audio Unit v3 inside AUM, GarageBand, Cubasis, Loopy Pro or any AUv3 host, or run it standalone. A TUNER THAT KNOWS ABOUT STRETCH Tune mode turns the scope into a tuner: it names the note it hears and shows how far sharp or flat it is in cents, with a ring that closes as you land on the pitch. It tunes against the stretch curve rather than equal temperament, so it follows a real instrument. Stretch shapes the overtones inside a note; Key Stretch makes the keyboard follow it, so octaves widen the way a piano's do. FOURTEEN TUNING SYSTEMS, AND A TEMPERAMENT EDITOR Equal and Just, five historical temperaments, and six from outside the European tradition including Maqam Rast, Turkish Rast, Slendro, Pelog and the Harmonic Series. The Temperament slider is a morph, not a switch: fully left is Just, fully right is whichever you chose. Twelve bars show any system as cents away from equal; drag one to make the tuning yours, then copy it out as plain text. Tunings save with the preset. FIVE HUNDRED SCALES Searchable by alternate name: malkauns, nikriz, bhupali and freygish find the right set. THE PARTIALS ARE THE INSTRUMENT The partials display shows every overtone in your sound, and four tools work on it directly. FOLD sweeps upper partials below the fundamental, redistributing energy across harmonic layers — not a filter. The OVERTONE SCAN steps a spotlight through individual partials with triangle, saw or random patterns, and can visit only partials in the active scale. The HARMONIC GATE reinforces partials whose pitch class matches your chord and suppresses the rest: capture a chord, follow MIDI, split the keyboard, or pick the notes on the gate's own keys. SCULPT draws the level and pan of every partial, slides the curve up the grid as a formant, and locks partials in place while the rest moves. THE HARMONIC VOCODER Pass live input or a sample through the synth as an effect. Your sound travels through a bank of tuned peaking bells rather than being replaced by filtered noise: open the Air and the source stays dry, tighten it and the bands resonate into it. Key Track is the mode switch: on it plays as an instrument, off it is a fixed filter you can sweep. Aimed at a sample, the bands track that sample's spectrum as it evolves. One level-matched Blend control crossfades it against the oscillators. PULSE-WIDTH MODULATION Set the core to a saw and Source 2 to a saw: the two ramps subtract, which is what a pulse wave is, and the phase between them sets the duty cycle. Modulate it and you have PWM. A preset in the Utility folder is ready to play. MODULATION A cog on almost every control, so the synth's own engine can drive nearly anything in the interface, including the display. Sources include velocity, envelopes, LFOs, how many notes you hold, how many oscillators sound, the synth's own output level, and Atmo, a shape driven by 84 years of barometric weather data from the Beat Kitchen Weather Sonification Project. Rates run from audio rate down to cycles that span years. THE SCOPE A stereoscope, oscilloscope, spectrum and a live per-partial display. Glow takes the trace from a hard line to a diffuse bloom, Colour sets the hue, Trace Speed and Dot set how it draws — and every one is a modulation target. Route velocity to Colour and the trace shifts as you play. LIVE INPUT A headphone button passes the side-chain straight to the output, so you can hear and see your input with nothing held: green when signal arrives, amber when a bus is connected but silent, red when nothing is. Resynth Speed locks a sample's playback speed to pitch, tape-style, or keeps them independent. Every control has a tooltip, presets work offline, and a harmony wheel follows what you play. One purchase, every update. Made by Beat Kitchen, a music production and teaching community.
HeadStack
This app offers a virtual tape loop with 8 independently configurable playback heads for creating diverse echo effects. It captures the warmth of classic tape machines while offering modern flexibility for sound design, from vintage echoes to evolving ambient textures.
- Multi-head tape engine with 8 playback heads
- Vintage tape character and imperfections
- Independent control for each playback head
- Rotating head wheel for dynamic effects
- Granular harmony engine for pitch-shifted textures
- Per-head modulation and creative feedback routing
- Diffusion and smearing for atmospheric washes
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HeadStack is a multi-head tape delay inspired by the character, movement and musicality of classic magnetic echo machines, reimagined for modern production. At its heart is a virtual tape loop with 8 independently configurable playback heads. Each head can be positioned, levelled and panned to create everything from vintage slap-back echoes and rhythmic repeats to vast stereo soundscapes and evolving ambient textures. While HeadStack captures the warmth and unpredictability of classic tape systems, it is not limited by their mechanical constraints. Individual heads can be modulated, filtered, diffused, pitch-shifted and transformed into granular playback engines, opening up a palette that ranges from authentic analogue echoes to shimmering harmonies and cinematic atmospheres. The tape itself becomes an instrument. Rotate the head wheel to continuously reposition playback points, stretch the spacing between heads, introduce head loss, or create cascading feedback networks that evolve with every repeat. Independent filtering, stereo placement and modulation allow each head to develop its own character within the delay line. You can even play sequences Into HeadStack and freeze it using your hold pedal and continue to play over the top. Whether you’re searching for vintage tape ambience, rhythmic multi-tap delays, lush granular harmonies or experimental feedback textures, HeadStack combines the soul of a classic tape echo with the flexibility of a modern creative effects processor. Welcome to a new generation of tape delay. HeadStack Features: Multi-Head Tape Engine - Create complex rhythmic delays using multiple independently controllable playback heads running on a shared virtual tape loop. Vintage Character - Capture the warmth, movement and musical imperfections of classic tape echo machines with adjustable tape loss, filtering and feedback behavior. Independent Head Control - Each playback head features its own level, pan, timing offset and tonal shaping, allowing intricate delay patterns and evolving stereo textures. Rotating Head Wheel- Continuously reposition or stretch the virtual head arrangement to create shifting rhythms, moving echoes and dynamic performance effects. Granular Harmony Engine - Transform individual heads into pitch-shifted granular voices, generating harmonies, octave layers and shimmering textures directly from the tape loop. Per-Head Modulation - Add movement and expression with independent modulation of playback position, spacing, tremolo and stereo placement. Creative Feedback Routing - Choose between traditional multi-head feedback or route feedback from a specific playback head for unique echo patterns and evolving repeats. Diffusion & Smearing - Blend between precise rhythmic echoes and spacious, atmospheric washes using integrated diffusion processing. Deep Stereo Imaging - Create anything from focused mono echoes to wide immersive soundscapes with per-head panning, Haas delay and stereo enhancement controls. Performance Ready - Designed for real-time interaction, encouraging hands-on manipulation of head positions, modulation and feedback while performing. Precision & Experimentation - Dial in authentic tape echoes, lush ambient delays or push the engine into unpredictable granular and feedback-driven territories. Modern Workflow - Combines the immediacy of classic hardware with the flexibility, recall and precision expected from a contemporary audio plugin. Interactive Head Wheel - Grab and rotate the virtual head wheel to reposition playback heads, create evolving delay patterns and perform dramatic tape-style scrubbing effects. Dynamic Tape Warping- Enable Rotate and Stretch modes to continuously morph the spacing and timing between playback heads, transforming static echoes into living, breathing rhythmic textures. Freeze Buffer - Freeze the contents of the audio buffer using a foot pedal, capture ideas and play over the top.
Screenshots
Verdict
The clearest difference is price: Beat Kitchen Harmonic Synth at Free against HeadStack's $12.99. Beat Kitchen Harmonic Synth also leads on update cadence (every 3 days vs every 9 days). HeadStack's advantage is in-app purchases (none vs 1) and chart position (#184 vs unranked). On rating, review sentiment, ratings volume and ads there is nothing between them.
Scored on Price · Rating · Positive reviews · Number of ratings · Update frequency · Ads · In-app purchases · Monetization · Best chart rank · Devices · Requires iOS
Beat Kitchen Harmonic Synth is free to download; HeadStack costs $12.99 up front. Beat Kitchen Harmonic Synth sells 1 one-off in-app purchase. HeadStack asks for nothing beyond the download.
On the App Store both sit at effectively the same score — 4.8 for Beat Kitchen Harmonic Synth against 4.8 for HeadStack. Both are backed by a comparable volume of ratings — 12 and 5 respectively. Written reviews split almost evenly too, at 100% and 100% positive.
Beat Kitchen Harmonic Synth ships an update every 3 days, HeadStack every 9 days. The most recent releases landed on October 12, 2026 and October 3, 2026 respectively.
| Parameter | Beat Kitchen Harmonic Synth | HeadStack |
|---|---|---|
| Price | Free — better | $12.99 |
| Rating | 4.8 (12 ratings) | 4.8 (5 ratings) |
| Positive reviews | 100.0% of reviews | 100.0% of reviews |
| Number of ratings | 12 — better | 5 |
| Update frequency | Every 3 days — better | Every 9 days |
| Ads | No | No |
| In-app purchases | Yes | No — better |
| Monetization | Free with in-app purchases — better | Paid |
| Best chart rank | — | #184 — better |
| Devices | iPhone, iPad | iPhone, iPad, iPod — better |
| Requires iOS | 16.0 | 14 — better |
| Further details — not scored | ||
| Size | 60 MB | 25 MB |
| Age rating | 4+ | 4+ |
| Developer | Beat Kitchen LLC | 4Pockets.com |
Customer experience
Beat Kitchen Harmonic Synth
HeadStack
In-app purchases
Beat Kitchen Harmonic Synth
- Full Unlock$14.99
HeadStack
No in-app purchases
Questions
Is Beat Kitchen Harmonic Synth free?
Is HeadStack free?
Which has better reviews, Beat Kitchen Harmonic Synth or HeadStack?
Do Beat Kitchen Harmonic Synth or HeadStack have ads?
Which is updated more often, Beat Kitchen Harmonic Synth or HeadStack?
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