Comparison

GSDSP Quantum Delay vs spectwhirl

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

Head to head
About

GSDSP Quantum Delay

This app offers a vintage-inspired stereo delay effect with advanced modulation, flexible filtering, and precise timing controls. It allows users to sculpt unique echo textures, from warm analog sounds to complex, evolving soundscapes.

Highlights
  • Vintage-inspired stereo delay
  • Deep modulation system
  • Flexible filtering (LPF, HPF, BPF)
  • Precise timing controls (BPM, ms)
  • Switchable stereo/dual mono modes
  • Advanced modulation sources (LFO, Random, Envelope)
Features
Read full description

A vintage-inspired delay supercharged with deep modulation, flexible filtering, and creative timing that pushes echoes into new dimensions. Classic Delay, Reinvented Quantum Delay takes the charm of a vintage stereo delay and fuses it with our next-level modulation system. Switch between the warm character of Tape mode and the pristine clarity of Fade mode, lock to BPM (including 5-tuplets) or dial in precise times in milliseconds. Use the Fine control for subtle push-and-pull micro-timing — or modulate your delay lines in ways traditional delays could only dream of. Sculpted Echoes Shape your repeats with switchable lowpass, highpass, and bandpass filters placed directly in the feedback path. Add modulation to create evolving tones, gentle movement, or drifting, frequency-shifting echoes. From warm analog-style rolls to shimmering, swirling textures, it’s all there. Feedback with Precision Control your delay tail behavior using either traditional % feedback or our modern dB-per-second decay system — ideal for predictable, musical decay even when the feedback path becomes complex. Enable Crossfeed for classic ping-pong stereo bounce, or push into Over-Feedback to create dense, self-building echoes that drift toward infinity. Stereo or Dual Mono Every section of Quantum Delay — delay, filter, and feedback — can switch between stereo and dual mono modes. Create tight, controlled stereo images or break them apart for wide, offset, unpredictable spaces. Dual mono modulation unlocks complex stereo interplay and beautifully asymmetric echoes. Modulation Without Limits Quantum Delay integrates our advanced modulation system, letting you modulate nearly anything: delay time, filters, feedback parameters, stereo controls, and more. Use LFOs, Random Generators, 2D modulators, Envelope Followers, Macros, and even chaotic systems to push your echoes far beyond traditional delay behavior. Or use our parameter randomisation feature to explore the plugin’s sound at random. Quantum Delay is an AUv3 audio effect plugin compatible with Logic Pro, AUM, Cubasis, GarageBand and many more. A Desktop version is also available for Windows and macOS (VST3 / AU / AAX). More information here: https://gs-dsp.com/products

About

spectwhirl

This audio effect app transforms input sound into new textures and bell-like tones by extracting and manipulating sinewave components. It offers advanced control over delay lines, frequency shifting, and filtering, with gesture recording for parameter automation.

Highlights
  • Sinewave component extraction and grouping
  • Delay lines with feedback
  • Frequency shifter and sample-and-hold effects
  • Configurable filtering
  • Gesture recording for automation
  • Scene saving and management
Features
Read full description

"bells and whistles, literally" spectwhirl is a hybrid spectral audio effect. It can extract and rearrange sinewave components from input signal to make new sound textures and bell-like sounds. * input sound is converted to sinewave components that are divided into 4 groups: harmonic, inharmonic, 12-edo and other * each component is fed into a delay line with feedback * there is a group of frequency shifter and sample-and-hold effects before and after delay lines * each set of sinewave components can be filtered * all the parameters can be instantly automated with gesture recording !!! Please note that this effect consumes much CPU and requires a modern device. ====================== Quick Start: Top row of controls enables different parts of user interface: scenes editor ("scene"), controls switch ("edit") and "zoom" controls When "edit" is switch on, you can show or hide various controls (marked as "ctrl") and switch gesture recording automation for some of them (marked with ">") Main control surface displays sonogram with tracked elements. Colors are set accordingly to the group they are assigned (red-orange-green-blue are for harmonic, inharmonic, 12-edo and others). Each "lane" contains delay time controls. * Triangle facing left is for the start locator, it determines initial delay time * Square moves both start and end locators together * When left locator is first moved you can see the right locator with the same triangle. It shows the end of the selected region, the secondary delay time is determined by the difference between left and right locators * if you drag over the area of the region in a lane, the four-dotted/one circle indicator will change its appearance; this changes the arpeggio mode of the region. If set to leftmost position (one circle) the components go in-sync; if set to maximum value (shown as diagonal line with circles) - components are played sequentially * all settings can be stored as "scene" and multiple scenes can be switched sequentially; there is a set of button to move, add and delete scenes. All scenes will be stored as machine state; it can be exported / imported as a single file or as separate file with current scene in the "setup" view The standalone version always starts with output level set to -70 dB to avoid feedback

Screenshots

GSDSP Quantum Delay3 screens
spectwhirl4 screens

Verdict

The call

The clearest difference is review sentiment: GSDSP Quantum Delay at 100% against spectwhirl's 33%. GSDSP Quantum Delay also leads on rating (4.8 vs 4.0) and ratings volume (17 vs 5). spectwhirl's advantage is price ($4.99 vs $14.99). On update cadence, ads, in-app purchases and monetization model 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

GSDSP Quantum Delay costs $14.99 and spectwhirl $4.99 up front. Neither carries in-app purchases, so what you see is what you pay.

ReceptionRating · Positive reviews · Number of ratings

GSDSP Quantum Delay holds the better App Store score, 4.8 against 4.0. Both are backed by a comparable volume of ratings — 17 and 5 respectively. Written reviews point the same way: 100% of GSDSP Quantum Delay's written reviews are positive against 33% of spectwhirl's.

UpkeepUpdate frequency

Both ship on a similar rhythm, roughly every 5 weeks. The most recent releases landed on September 22, 2026 and September 24, 2026 respectively.

Scorecard4 real differences · 6 level
GSDSP Quantum Delay versus spectwhirl: the parameters behind the verdict, then further details
ParameterGSDSP Quantum Delayspectwhirl
Price$14.99$4.99 — better
Rating4.8 (17 ratings) — better4.0 (5 ratings)
Positive reviews100.0% of reviews — better33.3% of reviews
Number of ratings17 — better5
Update frequencyEvery 5 weeksEvery 5 weeks
AdsNoNo
In-app purchasesNoNo
MonetizationPaidPaid
DevicesiPhone, iPad, iPodiPhone, iPad, iPod
Requires iOS12.012.0
Further details — not scored
Size94 MB7 MB
Age rating4+4+
DeveloperGustav ScholdaAlexey Nadzharov

Customer experience

GSDSP Quantum Delay

All ratings17 ratings
Positive94.1%
Neutral0.0%
Negative5.9%
Written reviews4 reviews
Positive100.0%
Neutral0.0%
Negative0.0%

spectwhirl

All ratings5 ratings
Positive60.0%
Neutral20.0%
Negative20.0%
Written reviews3 reviews
Positive33.3%
Neutral33.3%
Negative33.3%

In-app purchases

None

GSDSP Quantum Delay

No in-app purchases

None

spectwhirl

No in-app purchases

Questions

Is GSDSP Quantum Delay free?
GSDSP Quantum Delay costs $14.99, with no in-app purchases.
Is spectwhirl free?
spectwhirl costs $4.99, with no in-app purchases.
Which has better reviews, GSDSP Quantum Delay or spectwhirl?
GSDSP Quantum Delay is rated higher. GSDSP Quantum Delay averages 4.8 out of 5 from 17 ratings, while spectwhirl averages 4.0 from 5 ratings.
Do GSDSP Quantum Delay or spectwhirl have ads?
Neither GSDSP Quantum Delay nor spectwhirl shows ads.
Which is updated more often, GSDSP Quantum Delay or spectwhirl?
GSDSP Quantum Delay ships an update every 5 weeks, and spectwhirl every 5 weeks. Most recently, GSDSP Quantum Delay was updated on September 22, 2026 and spectwhirl on September 24, 2026.

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