# TB Lowtone — Bass synthesizer

> Advanced bass synthesizer with loudness-domain harmonic synthesis and AI patch generation. (iPhone/iPad app by ToneBoosters.)

- Source: https://appshunter.io/ios/app/tb-lowtone/id6448315127 (this page in markdown: same URL + `.md`)
- Developer: [ToneBoosters](https://appshunter.io/developer/1472446500)
- Category: Music, Entertainment
- Price: $9.99
- Rating: 4.40/5 from 14 App Store ratings · 13 written reviews indexed
- Age rating: 4+
- Requires: iOS 13.0 · 13 MB
- Released: 2023-06-23
- Data updated: 2026-08-27
- Monetization: paid
- User reviews in markdown: https://appshunter.io/ios/app/tb-lowtone/id6448315127/reviews.md

## What is TB Lowtone?

TB Lowtone is an innovative bass synthesizer app and AUv3 plug-in featuring three analog-simulated, voltage-controlled oscillators with a large variety of waveform algorithms, continuous pulse-width modulation (PWM), Frequency Modulation (FM) and oscillator hard sync, complemented by a voltage-controlled noise synthesizer, parameter modulation a re-designed non-linear voltage controlled filter. 

TB Lowtone is the world's first bass synthesizer featuring loudness-domain harmonic synthesis, creating deeper, more consistent and production-ready bass sounds compared to conventional synthesizers operating in the (linear) amplitude domain. 

TB Lowtone also features an AI randomizer that generates new patches with a single click, and which learns from the patches you have already created to generate new, personalized patches!


Loudness-domain synthesis
Loudness perception of tones and harmonics is known to be highly non-linear and intricately frequency and level dependent. Equal loudness contours, or Fletcher-Munson curves demonstrate this drastic effect for sine tones, which is especially relevant for low frequencies.

The loudness of a synthesizer bass note, and all its individual harmonics, will therefore depend strongly on what note you play on your synth's keyboard. 

To overcome the resulting inconsistencies in loudness and timbre, TB Lowtone features innovative, loudness-domain synthesis algorithms that adjust each harmonic individually to compensate for loudness deviations across frequency.


Modulation and FX
TB Lowtone provides two extended low-frequency oscillators (X-LFOs) featuring a wide range of waveforms. The LFOs can be beat and key synced, with a configurable onset delay and a specific number of cycles to run.

In addition, a conventional ADSR envelope with configurable onset delay is provided. To top if all off, a gate editor designed to quickly put together modern production modulation patterns is available as well to modulate a range of VCO, VCN and VCF parameters.

Reverb, chorus, and delay effects and a high-quality peak limiter are provided to produce production-ready sounds.


Features:
- 3 VCOs plus a VCN featuring a wide range of waveform algorithms
- All VCOs support hard sync, pulse-width modulation (PWM) and frequency modulation (FM)
- Lots of filter types for spectral shaping
- 2 LFOs, one extra envelope and a gate editor for parameter modulation
- Pro quality effects (reverb, chorus, delay, peak limiter)
- Unique loudness domain synthesis algorithms
- A smart randomiser that learns from your patches
- AUv3 with resizable UI and dozens of color themes to choose from
- Preset management including import and export options
- Undo, redo, A/B switching


What you should know:
- Licenses acquired for this platform are not compatible with other platforms.
- Audio Unit (AUv3) extensions require an iPad mini 2, iPad 4 or later models.

## Key features

- Loudness-domain harmonic synthesis
- 3 analog-simulated oscillators
- Voltage-controlled noise synthesizer
- AI randomizer for patch generation
- Extended LFOs and ADSR envelope
- Pro quality effects (reverb, chorus, delay)
- AUv3 plugin support

## Chart rankings

- #191 in Top Paid · Music (US App Store)

## Recent user reviews (10 of 13)

All indexed reviews: https://appshunter.io/ios/app/tb-lowtone/id6448315127/reviews.md

### 4/5 — Ótimo

*2026-03-12*

App muito bom! Várias opções para montar seu synth, porém senti falta da opção mídi learn pelo menos para o volume master! Ao utilizar com o controlador preciso interagir com o app para ajustar o volume e isso acaba piorando a experiência no ao vivo

### 3/5 — Ever get fixed

*2026-01-08*

Never stops running on back ground flow n lowtones have them on android really need here but has to delete never stopped running even when I rest n all ate up 1k hours in background just added up everyday not even using them run all night plugged in crazy?? Has it been fixed to show up in no background refresh yet both of em please how can apps even do that

### 5/5 — Great on android

*2025-10-17*

Has got way better or I learned some tricks lol tyty

### 3/5 — Great on android

*2025-10-12*

Since they day I bought on iPhone we’re I more need them they run when the want and all night long every night even tried low battery mode last night with all app background refresh off always is Flowtones and low tones no place to be found? So they do as they please going to ruins my battery even if I don’t open them? Any help please

### 4/5 — Not showing up in App Lists runs 24/7

*2025-10-10*

Been running all day last 11 plus hours on background these apps need to be able to be on the list to not run in background on iOS why? I love low and flow tones I’m in witch’s but dang why? Edit working better today we’ll see if I’m ever charged up n leave it in plugged it never does that but clearly the two apps will. Oops spoke to soon been running two hours in background while off lol App is great would of got 5 stars from android to here but on iPhone it and Flowtones just ran all night and killed my battery why? And why do they not show up with all other apps to turn off app background refresh??? It’s like they don’t even exist on my phone but they work 5 stars on android has a bug or sum in them here I guess I’ll have to run phone in low battery mode to kill background but two days n a row and I know for sure now same two apps that don’t pop up in app refresh to turn it off showed tan all night and ate my battery up. Sad I love the apps couldn’t wait to get them here smh

### 4/5 — Great sound design depth, but needs a collapsible keyboard

*2025-10-07*

TB Lowtone is a fantastic-sounding synth with a smooth interface and tons of modulation options, but on iPad the fixed on-screen keyboard takes up too much space. It would be great to have a “hide keyboard” toggle so the main panel can expand fully, especially when using an external MIDI controller or hosting it inside another app. A simple UI control for that would make Lowtone feel far less cramped and even more enjoyable to tweak.

### 4/5 — No Velocity+Volume ?

*2025-02-15*

Velocity Control volume?

### 4/5 — 🚨🚨🚨🚨🚨🚨🚨🚨🚨🚨🚨🚨🚨🚨🚨🚨🚨🚨

*2024-11-05*

Can you Please add a star favoring system to presets?  I’m sure everyone will find this very helpful.

### 5/5 — Doch einen Kauf wert

*2024-01-08*

Allein die Loudness Domain spezifische Berücksichtigung scheint mir ein echter Gewinn zu sein. Ich habe erst spät zugegriffen, da ich dachte es gäbe ein viel zu großes Überschneiden mit Flowtones desselben Entwicklers. Aber Nö, absolut alles richtig gemacht. Und da (selbstverständlich) auf Win/Mac verfügbar, wird das auch wieder in den Workflow integriert.

### 5/5 — Another winner from ToneBoosters

*2023-11-03*

Lowtone has quickly become the monosynth I reach for first when I’m starting a new project. Beautiful lush layered tones. A really excellent noise generator. Great filter section. Super fun and easy gate effect. Tons of great sounding presets serve as easy jumping off points for sound design. 

I wish there was round-trip preset compatibility between the iOS and Mac versions of Lowtone in Logic (i.e. I wish the Mac version included an AUv3) but other than that this is just a fantastic instrument.

## Frequently asked questions about TB Lowtone

### What makes TB Lowtone's synthesis unique?

TB Lowtone utilizes loudness-domain harmonic synthesis, a world-first for bass synthesizers. This approach compensates for loudness deviations across frequencies, resulting in more consistent and production-ready bass sounds compared to traditional amplitude-domain synthesizers.

### How does the AI randomizer in TB Lowtone work?

The AI randomizer in TB Lowtone generates new patches with a single click. It learns from your existing patches to create personalized and novel sound designs, offering a creative boost for users.

### What are the system requirements for TB Lowtone's AUv3 functionality?

To use TB Lowtone as an Audio Unit (AUv3) extension, you will need an iPad mini 2, iPad 4, or a later model. Licenses acquired for this platform are not compatible with other platforms.

### What kind of modulation capabilities does TB Lowtone offer?

TB Lowtone provides two extended low-frequency oscillators (X-LFOs) with various waveforms, a conventional ADSR envelope, and a gate editor for parameter modulation. These tools allow for complex and dynamic sound shaping.

### Does TB Lowtone include built-in effects?

Yes, TB Lowtone comes equipped with professional-quality effects including reverb, chorus, and delay. It also features a high-quality peak limiter to help produce polished, production-ready sounds.

### How often is TB Lowtone updated?

TB Lowtone was last updated on September 29, 2025, with version 1.2.7. This indicates a recent update, suggesting ongoing development and support for the application.

### What is the price of TB Lowtone?

TB Lowtone is available for a one-time purchase of $9.99. This price grants you access to all the features of the app.

### What devices is TB Lowtone compatible with?

TB Lowtone is compatible with iPhone, iPad, and iPod devices. It is designed for iOS and offers a resizable UI for different screen sizes.

## Version history (last 5 releases)

### 1.2.8 — 2026-05-28

This update provides significant workflow, customisation, personalisation and performance improvements:
- New MIDI learn function
- Improved detection of drag vs click/tap logic for UI elements
- Fix an issue with manual entry of automation lane values in certain hosts
- New option to enable highlighting of UI elements that accept keyboard input
- New option to customize color scheme
- Improved undo/redo functionality

### 1.2.7 — 2025-09-29

Stability and efficiency improvements

### 1.2.6 — 2025-09-21

Stability, compatibility, and efficiency improvements

### 1.2.4 — 2025-06-30

Stability and efficiency improvements

### 1.2.3 — 2025-04-11

New feature: 16 active program slots that can be changed using MIDI program messages

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## More apps by ToneBoosters

- [TB Equalizer](https://appshunter.io/ios/app/tb-equalizer/id1473111210)
- [TB Reverb](https://appshunter.io/ios/app/tb-reverb/id1474944185)
- [TB Barricade](https://appshunter.io/ios/app/tb-barricade/id1480150563)
- [TB ReelBus](https://appshunter.io/ios/app/tb-reelbus/id1482450479)
- [TB Enhancer](https://appshunter.io/ios/app/tb-enhancer/id1484449791)
- [TB Morphit](https://appshunter.io/ios/app/tb-morphit/id1487595036)

All apps by ToneBoosters: https://appshunter.io/developer/1472446500

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*Data collected daily from the US App Store and indexed by [AppsHunter](https://appshunter.io/). User reviews are verbatim App Store reviews. Ratings, prices and chart positions refresh continuously; this snapshot is from 2026-08-27.*