FAC Gravity vs OttavaBassa
Price, ratings, monetisation and update history for both apps, side by side — with what reviewers say about each.
FAC Gravity
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FAC Gravity AUv3 Plugin is a frequency shifter for creating Barberpole and Shepard style glissandos, spectral illusions, stereo rotation, chorusing, phasing, evolving echoes, infinite cosmic spaces, and all the combinations you’ll make. The plugin gives you two ways to process the audio source. In Stereo mode, each channel is shifted independently, with a Ratio control determining how closely their frequency shifts align. In Mono mode, FAC Gravity extends the internal quadrature processing to create a wide stereo image from the mono source. The frequency shift can move up or down, from subtle to more extreme spectral transformations. You can set the amount in Hz for classic Bode-style frequency shifting, make it follow your host tempo for rhythmic patterns, or even control it from MIDI notes for a more hands-on approach. A new dimension appears when you let the shifter feed back into itself with Spiral, a customizable loop with delay, blur, filtering, and different characters that shape how the sound circles, smears, interacts, and evolves over time. The result can range from bubbling textures to infinite sustained tones and noisy analog self-oscillation. Each character takes the feedback somewhere different. To dive deeper into new sonic dimensions, FAC Gravity comes with its own modulation module. The LFO, envelope follower, and flexible modulation matrix let you animate most parameters, from subtle evolving movements to complex, rhythmically reactive changes. You can even make the stereo field animate and rotate continuously by making the Width, Phase, and Pan parameters spin! You can shape the effect further by blending the processed signal with the original, while the optional limiter keeps the most extreme combinations in check. • Barberpole glissandos, spectral illusions, rotating stereo, evolving echoes • Dual Frequency Shifting, or Mono Shifting with Quadrature Stereo Widening • Organic Spiral Loop, from gentle feedback to pure analog self-oscillation • Integrated delay, diffusion blur, and independent low/high filtering • Modulation matrix, multi-source envelope follower • LFO with classic waveforms and random spline • Spinning modulation to rotate and animate the stereo field • Tempo-synced or MIDI-driven Frequency Shift, LFO, and Delay • Dry/Wet mix, optional limiting, and goniometer visualization • Advanced Responsive Design, portrait and landscape views • Universal Purchase: AUv3 for iOS (iPad/iPhone), macOS and Vision Pro The documentation is available at fredantoncorvest.com/FAC_Gravity.html This is an AUv3 Effect and requires a compatible host to work The in-app purchases are for tipping only, the app is fully functional without them
OttavaBassa
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OttavaBassa has been designed for guitarists looking for a simple all-in-one plugin solution for making their guitar sound like a bass. This means you could use your standard guitar to play bass lines on recordings and during live performances. OttavaBassa is an “Octaver” effect that takes your incoming note and transposes it down by one octave putting your instrument into the range of a bass guitar. In addition to the octave-down effect itself, OttavaBassa also includes a simple EQ voiced for controlling the important low and high bass guitar frequencies, as well as built-in effects for drive, compression, stereo chorus and a simple speaker cab filter. “Ottava bassa” is a music theory direction that literally translates as “low octave” or “octave below”. It is commonly abbreviated as “8vb”, hence the icon. OttavaBassa is an AUv3 effects plugin that can run standalone, or in any AUv3 compatible host such as Logic Pro, GarageBand or AUM. OttavaBassa currently runs on iPadOS / iOS (iPad & iPhone) and macOS (Intel & Silicon) and is available as a Universal Purchase from the Apple App Store. If you’re planning on using OttavaBassa on Mac / desktop, please ensure that your favourite DAW / host supports AUv3 (not just AU). PLEASE READ THIS SECTION CAREFULLY! OttavaBassa has been designed specifically for use with guitar. This means that pitches below the low E string (82.4Hz) will not be handled well. Sorry bass players! OttavaBassa will perform at its best when it is given single notes played reasonably cleanly and accurately. It is not a monophonic pitch generator in the true sense, but multiple input notes (aka chords) might result in “warbles” in the processed signal. OttavaBassa uses a pitch detection method that will introduce audio latency, i.e. a delay between input and output. Please note this is not to be confused with audio interface latency, so you cannot “fix” this by changing buffer sizes or sample rates in your host app. Currently OttavaBassa has a latency of around 25ms. So whether OttavaBassa will work for you, depends largely on your playing style and whether you can live with the inherent latency. My personal perspective: I would never make a plugin I wouldn’t use myself. In fact I made OttavaBassa because I needed an Octaver for my own iPad-based live guitar setup, and I couldn’t quite find what I was looking for. I find that OttavaBassa sounds good to me, and feels responsive enough in the context of a live performance, adding bass lines to guitar loops for example. I wouldn’t do a gig without it! I thought hard about making OttavaBassa publicly available because I’ve seen many Octaver plugins get terrible reviews from folks who don’t really understand that the latency and tracking limitations can’t really be magicked away with clever coding! While I am aware of more sophisticated pitch shifting DSP advances that significantly reduce latency especially, I believe this comes at a CPU cost. So while OttavaBassa does use a less sophisticated pitch detection method than “state of the art”, this does mean it’s pretty light on CPU (i.e. around 6% running on an M1 iPad in AUM). And of course, just because it was designed for guitar, doesn’t mean OttavaBassa won’t work on other audio sources - it can sound pretty scary on vocals for example! Just be mindful of the limitations mentioned above regarding pitch range and tracking, e.g., maybe don’t put an entire mix through it and expect amazing results! Thanks for reading to the end :-) -Rob
Screenshots
Verdict
The clearest difference is in-app purchases: OttavaBassa at none against FAC Gravity's 3. OttavaBassa also leads on price ($3.99 vs $8.49) and iOS requirement (13.0 vs 17.0). On ads 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
FAC Gravity costs $8.49 and OttavaBassa $3.99 up front. FAC Gravity sells 3 one-off in-app purchases. OttavaBassa asks for nothing beyond the download.
| Parameter | FAC Gravity | OttavaBassa |
|---|---|---|
| Price | $8.49 | $3.99 — better |
| Ads | No | No |
| In-app purchases | Yes | No — better |
| Devices | iPhone, iPad, Mac | iPhone, iPad, iPod, Mac — better |
| Requires iOS | 17.0 | 13.0 — better |
| Further details — not scored | ||
| Size | 4 MB | 18 MB |
| Age rating | 4+ | 4+ |
| Developer | Frederic Corvest | Rob Jackson |
In-app purchases
FAC Gravity
- Small Tip$1.99
- Medium Tip$4.99
- Large Tip$14.99
OttavaBassa
No in-app purchases
Questions
Is FAC Gravity free?
Is OttavaBassa free?
Do FAC Gravity or OttavaBassa have ads?
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