Comparison

Quantum Sequencer vs PhaseII

Price, ratings, monetisation and update history for both apps, side by side — with what reviewers say about each.

Head to head
About

Quantum Sequencer

This app offers an interactive approach to music composition, focusing on detailed steps that can be arranged into looping sequences. It provides extensive control over note parameters and allows for real-time manipulation and experimentation.

Highlights
  • Interactive step-focused composition
  • Detailed step notation (probability, ornamentation)
  • Configurable sequence lengths and sub-sequences
  • 16 general faders for parameter editing
  • MIDI learnable faders
  • Programmable loop actions
  • Per-sequence MIDI FX, devices, and controllers
Read full description

Quantum is a performance midi sequencer which approaches music composition with an interactive creation processes - sometimes referred to as 'noodling'. Where pattern or piano-role sequencers are good for music forms (intro/verse/chorus etc) or grid entry, Quantum's approach is built around the idea of a step being the focus - think of the step as a single note or chord written on a music sheet then add a lot of extra notation (like probability of playing or ornamentation say). These highly detailed steps are then aligned into sequences (think melodies) that loop. You can have any length up to 64, but these can be further split into 4 sub-sequences that have their own set of sequencer parameters (like tempo, play direction, transpose etc). To enter step parameters such as note pitch, velocity, gated length etc, 16 general faders are available which allow you to draw, drag, select copy/paste, inc/dec & link together to edit values. These are also midi learnable (midi cc or nrpn) to allow you to use control surfaces or midi controllers. To aid you with faster control Quantum has loop actions which you can program in to carry out tasks when a sequence loops - e.g. transpose, randomise, start or load another sequence etc. With up to 24 sequences playing Quantum introduces a mixer page allowing you to blend midi velocities. Built on the MidiSequencer engine, midi FX, devices & Controllers are now possible per sequence. So why would Quantum be good for your setup? There are many midi enabled IOS & hardware synths that produce exotic timbres if you send them fast & varied midi controls that you just would not hear with keyboard playing or slow tempo tunes. Also, Quantum, embraces experimentation in melody creation and by copy/pasting allowing quick setup of arpeggios & counterpoint tunes that you can create & manipulate on the fly! note : This app sends midi information - you need to use it in conjunction with any midi enabled iOS synth app (e.g. Sunrizer) to hear sounds

About

PhaseII

This audio effect plugin offers a dual stereo phaser with a vintage sound. It allows for independent phasing engines in parallel or series, with selectable modes for subtle to extreme effects. Controls include rate, depth, width, drive, and mix for versatile sound shaping.

Highlights
  • Dual stereo phasing engines
  • Parallel and series processing modes
  • Selectable effect modes (subtle to extreme)
  • Adjustable rate, depth, and width
  • Optional drive for analog warmth
  • Soft limiting to prevent clipping
  • Mix control for wet/dry balance
Read full description

PhaseII Dual Stereo Phaser Plugin (AUv3) PhaseII is an audio effect plugin that can run standalone, or in any AU compatible host application such as Logic Pro, GarageBand or AUM. Overview PhaseII is a dual stereo phasing machine with a vintage vibe! As well as traditional super-wide stereo phasing effects, PhaseII can also produce all manner of swirly modulated goodness by running the independent phasing engines in parallel or series. Selectable modes allow quick access to finely-tuned settings under the hood that "just work", from subtle to extreme - just the thing if you find some phasers to be overly complex with too many parameters! Set Rate and Depth to taste, adjust the stereo Width, then you can even add some gritty Drive for some "analog" warmth. Controls Active - Bypasses the effect (Off) or selects one of the following processing modes: Stereo - Two independent phasers for the left and right channel, with LFOs 90 degrees out of phase for a stereo effect, determined by the Width control. Parallel - Two independent stereo phasers for the incoming audio, which are then summed together at the output stage. The LFOs for each of the four phasers are 90 degrees out of phase for a stereo effect, determined by the Width control. Series - Two independent stereo phasers with Phase I processing incoming audio, which is then passed on to Phase II for a double-helping of phasey goodness at the output stage! This is potentially the most dramatic phasing effect, especially with the Width set to maximum as each of the four phaser LFOs are 90 degrees out of phase. The following controls apply to each phase stage, referred to as Phase I or Phase II: Phase I/II - Toggles the Phase I or Phase II processing engine On or Off. Rate - Sets the rate of the phaser LFO in Hz. Depth - Sets the depth of the phase effect. Mode - Selects one of four different modes. Each mode configures several "under the hood" settings - think of each mode as a mini preset for internal parameters. Modes range from subtle (I) to extreme! (IV). The following controls are global: Width - Adjusts the stereo width from super-wide to monophonic. Note this only adjusts the "wet" phased sound so your original stereo image remains intact for the "dry" signal. Drive - Applies an optional amount of warm overdrive to the phaser processing only, for a bit of a vintage vibe! Mix - Balances the processed audio with the incoming / dry signal. At zero, the output is totally dry, and at 100%, the output is totally wet and phased to the max! The phasing effect can sometimes create loud resonant frequency peaks that could result in clipping. To protect against this, soft limiting is applied at both the phasing processing stage and at the final summed output. If the input levels are high, this can add to the "analog" like sound of PhaseII when compression and saturation occurs. About The UI Not everyone likes the UIs of my latest (2025) plugins - I get it. However, the simplistic and generic approach allows me to (a) 99% focus on the DSP, sound quality and CPU performance, and (b) significantly reduce the development (and potential maintenance) time, which is reflected in my pricing. For more info and support please visit: www.waverley-instruments.com/robjackson

Screenshots

Quantum Sequencer4 screens
PhaseII4 screens

Verdict

The call

The clearest difference is review sentiment: PhaseII at 100% against Quantum Sequencer's 69%. PhaseII also leads on rating (5.0 vs 4.6) and price ($1.99 vs $7.99). Quantum Sequencer's advantage is ratings volume (35 vs 2). 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

CostPrice · In-app purchases · Ads · Monetization

Quantum Sequencer costs $7.99 and PhaseII $1.99 up front. Neither carries in-app purchases, so what you see is what you pay.

ReceptionRating · Positive reviews · Number of ratings

PhaseII holds the better App Store score, 5.0 against 4.6. That said, the two scores are not equally well evidenced: Quantum Sequencer has 35 ratings behind it against 2, so its average is the more settled of the two. Written reviews point the same way: 69% of Quantum Sequencer's written reviews are positive against 100% of PhaseII's.

UpkeepUpdate frequency

Quantum Sequencer ships an update every 6 weeks, PhaseII every 9 days. The most recent releases landed on September 19, 2026 and September 8, 2026 respectively.

Scorecard5 real differences · 5 level
Quantum Sequencer versus PhaseII: the parameters behind the verdict, then further details
ParameterQuantum SequencerPhaseII
Price$7.99$1.99 — better
Rating4.6 (35 ratings)5.0 (2 ratings) — better
Positive reviews68.8% of reviews100.0% of reviews — better
Number of ratings35 — better2
Update frequencyEvery 6 weeksEvery 9 days — better
AdsNoNo
In-app purchasesNoNo
MonetizationPaidPaid
DevicesiPhone, iPad, iPodiPhone, iPad, iPod, Mac — better
Requires iOS12.012.0
Further details — not scored
Size191 MB13 MB
Age rating4+4+
Developeranthony saundersRob Jackson

Customer experience

Quantum Sequencer

All ratings35 ratings
Positive88.6%
Neutral2.9%
Negative8.6%
Written reviews32 reviews
Positive68.8%
Neutral9.4%
Negative21.9%

PhaseII

All ratings2 ratings
Positive100.0%
Neutral0.0%
Negative0.0%
Written reviews2 reviews
Positive100.0%
Neutral0.0%
Negative0.0%

In-app purchases

None

Quantum Sequencer

No in-app purchases

None

PhaseII

No in-app purchases

Questions

Is Quantum Sequencer free?
Quantum Sequencer costs $7.99, with no in-app purchases.
Is PhaseII free?
PhaseII costs $1.99, with no in-app purchases.
Which has better reviews, Quantum Sequencer or PhaseII?
PhaseII is rated higher. Quantum Sequencer averages 4.6 out of 5 from 35 ratings, while PhaseII averages 5.0 from 2 ratings.
Do Quantum Sequencer or PhaseII have ads?
Neither Quantum Sequencer nor PhaseII shows ads.
Which is updated more often, Quantum Sequencer or PhaseII?
Quantum Sequencer ships an update every 6 weeks, and PhaseII every 9 days. Most recently, Quantum Sequencer was updated on September 19, 2026 and PhaseII on September 8, 2026.

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