DRM vs Sirens' Chor
Price, ratings, monetisation and update history for both apps, side by side — with what reviewers say about each.
DRM
This app emulates a vintage 1978 drum machine, offering a pocket beat-making companion with a pure, distraction-free interface. It includes original samples, preset patterns, and various instrument and audio effects.
- 8 original high-quality double-samples
- 16 preset patterns
- Selective instrument deletion modes
- Commutable 'Spacedrum' instrument
- Full machine state auto-save
- Background audio playback
- Audiobus V3 and InterApp audio support
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Holding the simplicity of a rare 1978 instrument and carrying its raw heritage to you, it turns your device into a pocket beat making companion. I believe that designing a pure interface, simply displaying your machine without any distraction, was the best way to reflect the spirit of the period it was born. Characteristics : - 8 Original high quality double-samples - 16 preset patterns - 3 Selective instrument deletion modes - Commutable « Spacedrum » instrument - Full machine state auto-save - Background audio playback enabled - Audiobus V3 - InterApp audio Bonuses accessible in your device settings : - Additionnal LED display for the tempo and the volume - Pattern selection LED indicators - Alternative « Rock » drum kit with integrated effects - Built-in intruments effects : « Stereo pan » and « Jungle tune » - Built-in audio effects : « Equalizer » and « Distortion » - Built-in global effects : « Delay » and « Reverb » - Mute any instrument I hope you will enjoy it as much as I love it ;-)
Sirens' Chor
This experimental audio effect app analyzes input audio to generate a secondary harmonic voice using sine wave oscillators. The generated voice can be mixed with the original or played solo, creating a chorus effect. It's CPU intensive and operates within a specific frequency range.
- Harmonic analysis of input audio
- Sine wave oscillator synthesis
- Adjustable chorus effect
- Second voice generation
- AUV3 plugin support
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This one is quite experimental and CPU heavy app! While working on my Chord Detector app I came up with the idea to play the found harmonics with sine wave oscillators so I can hear what the algorithm is hearing :) It turns out to be an interesting output that led me to creation of this audio effect app. What happens here is that the input is analysed for main harmonics in the range of 80Hz to 1500Hz. Then a series of sine wave oscillators are set to play those harmonics with the exact frequency and volume and their output is added to create a second voice. This second voice can then be mixed with the input to create some kind of chorus or played alone. All this is CPU heavy process so it should be used with care... Also to make this effect possible I had to use limited range 80Hz to 1500Hz so it is not suitable for every instrument and you have to keep that range in mind when producing. Some very fast volume and frequency changes are applied to the oscillators. The app is AUV3
Screenshots
Verdict
The clearest difference is review sentiment: Sirens' Chor at 100% against DRM's 38%. Sirens' Chor also leads on rating (4.0 vs 3.7) and iOS requirement (10.0 vs 12.0). DRM's advantage is update cadence (every 7 months vs every 39 months) and price ($0.99 vs $3.99). On ads, in-app purchases, monetization model and device support 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
DRM costs $0.99 and Sirens' Chor $3.99 up front. Neither carries in-app purchases, so what you see is what you pay.
Sirens' Chor holds the better App Store score, 4.0 against 3.7. That said, the two scores are not equally well evidenced: DRM has 12 ratings behind it against 2, so its average is the more settled of the two. Written reviews point the same way: 38% of DRM's written reviews are positive against 100% of Sirens' Chor's.
DRM ships an update every 7 months, Sirens' Chor every 39 months. Both last shipped on October 24, 2026.
| Parameter | DRM | Sirens' Chor |
|---|---|---|
| Price | $0.99 — better | $3.99 |
| Rating | 3.7 (12 ratings) | 4.0 (2 ratings) — better |
| Positive reviews | 38.5% of reviews | 100.0% of reviews — better |
| Number of ratings | 12 — better | 2 |
| Update frequency | Every 7 months — better | Every 39 months |
| Ads | No | No |
| In-app purchases | No | No |
| Monetization | Paid | Paid |
| Devices | iPhone, iPad, iPod | iPhone, iPad, iPod |
| Requires iOS | 12.0 | 10.0 — better |
| Further details — not scored | ||
| Size | 23 MB | 11 MB |
| Age rating | 4+ | 4+ |
| Developer | David Rochaix | Aleksandar Mlazev |
Customer experience
DRM
Sirens' Chor
In-app purchases
DRM
No in-app purchases
Sirens' Chor
No in-app purchases









