ab Astrometry X vs PolyDelay
Price, ratings, monetisation and update history for both apps, side by side — with what reviewers say about each.
ab Astrometry X
This advanced audio effect offers dynamic multitap delay with randomized tap positioning around the listener. Control tap viscosity, time, and loudness intuitively via an XY pad. Create custom delay lines by syncing to your DAW or using free time, in serial or parallel modes.
- Random tap positioning
- Viscosity, Time, and Loudness control
- Intuitive XY Pad design
- DAW sync or free time
- Serial or parallel mode
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ab Astrometry X is an Advanced Multitap Delay with random positioning of each tap around the listener's head. Each tap comes with a variables Viscosity, Time and Loudness controllable through an intuitive XY Pad Design. Each tap's time can be set to be synced to the DAW or with free time, in serial or parallel mode - allowing users to create custom and creative Delay lines.
PolyDelay
This audio effect plugin creates unique polyrhythmic delays and familiar delay patterns. It syncs to host tempo and offers advanced tone-shaping options like filters and modulation.
- Polyrhythmic delay calculations
- Host tempo sync
- Dual delay lines
- Stereo width control
- High and low pass filters
- Stereo modulation
- Internal limiting
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PolyDelay Polyrhythmic Delay Plugin (AUv3) PolyDelay is an audio effect plugin that can run standalone, or in any AU compatible host application such as Logic Pro or GarageBand. Overview PolyDelay is a dual delay line / stereo effect with optional host tempo sync. While PolyDelay can be used to create interesting stereo polyrhythmic delays, it can also produce more familiar delay patterns such as dotted eighth and quarter note triplets. Polyrhythms, Divisions and Beats PolyDelay calculates delay times based on a BPM (beats per minute) tempo, and the polyrhythmic notation of D:B, where D = divisions and B = beats. For example, 3:2 would mean that the time for 2 beats should be divided by 3. If you're more use to the idea of note lengths and delay times, such as quarter notes and dotted eighths, etc., this might be confusing at first, but hopefully this guide will help. Firstly, everything starts with the beat! So, for 120BPM, each beat (or quarter note) will be half a second, or 500ms. So if you want a quarter note delay, you want 1 division within one beat, so you would set Divs and Beats to 1. Here are some typical note values, lengths (120BPM) and their D:B values: 1/4 = 500ms = 1:1 (take the length of one beat, and divide that by one) 1/8 = 250ms = 2:1 (take the length of one beat, and divide that by two) 1/16 = 125ms = 4:1 (etc.) 1/32 = 63ms = 8:1 (etc.) See how the divisions are doubled-up for each note? And here are some dotted and triplet note examples - see how the D:B numbers start to get interesting! 1/4D = 750ms = 2:3 1/4T = 333ms = 3:2 1/8D = 375ms = 4:3 1/8T = 167ms = 3:1 A classic stereo delay would be 1:1 (1/4) left, and 4:3 (1/8D) right with Width set to max. If you want a really long delay, a 1:8 setting would give you 4 seconds at 120BPM with Multiply set to Normal, or 8 seconds set to Half. The Presets also include some typical (and not so typical!) examples to get you started. The fun really starts when you start mixing "unusual" (typically odd numbers) divisions and beats, such as 5:4 or 2:7. These sorts of relationships are what we typically refer to as polyrhythms. Try experimenting with PolyDelay on simple sequences and drum parts / patterns and you may start to hear all sorts of interesting rhythmic interplay as your brain tries to figure out what's going on! For additional tone-shaping, PolyDelay includes variable stereo width, a high and low pass filter, stereo modulation and internal limiting to keep audio levels in check. For more info and support please visit: www.waverley-instruments.com/robjackson
Screenshots
Verdict
The clearest difference is price: PolyDelay at $1.99 against ab Astrometry X's $12.99. PolyDelay also leads on update cadence (every 3 months vs every 7 months). 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
ab Astrometry X costs $12.99 and PolyDelay $1.99 up front. Neither carries in-app purchases, so what you see is what you pay.
On the App Store both sit at effectively the same score — 5.0 for ab Astrometry X against 5.0 for PolyDelay. Both are backed by a comparable volume of ratings — 6 and 3 respectively. Written reviews split almost evenly too, at 100% and 100% positive.
ab Astrometry X ships an update every 7 months, PolyDelay every 3 months. The most recent releases landed on September 8, 2026 and September 10, 2026 respectively.
| Parameter | ab Astrometry X | PolyDelay |
|---|---|---|
| Price | $12.99 | $1.99 — better |
| Rating | 5.0 (6 ratings) | 5.0 (3 ratings) |
| Positive reviews | 100.0% of reviews | 100.0% of reviews |
| Number of ratings | 6 — better | 3 |
| Update frequency | Every 7 months | Every 3 months — better |
| Ads | No | No |
| In-app purchases | No | No |
| Monetization | Paid | Paid |
| Devices | iPhone, iPad, iPod | iPhone, iPad, iPod, Mac — better |
| Requires iOS | 12.0 | 12.0 |
| Further details — not scored | ||
| Size | 9 MB | 13 MB |
| Age rating | 4+ | 4+ |
| Developer | Alejandro Cabrera Zuniga | Rob Jackson |
Customer experience
ab Astrometry X
PolyDelay
In-app purchases
ab Astrometry X
No in-app purchases
PolyDelay
No in-app purchases









