# Audio Kit — Audio Testing App > Comprehensive audio analysis toolkit with spectrum analyzer, scope, SPL meter, and signal generator. (iPhone/iPad app by Sinusoid Pty Ltd.) - Source: https://appshunter.io/ios/app/audio-kit/id376965050 (this page in markdown: same URL + `.md`) - Developer: [Sinusoid Pty Ltd](https://appshunter.io/developer/364871696) - Category: Music, Utilities - Price: $2.99 with in-app purchases - Rating: 3.50/5 from 6 App Store ratings · 38 written reviews indexed - Age rating: 4+ - Requires: iOS 15.6 · 2 MB - Languages: Australian English - Released: 2010-06-18 - Data updated: 2026-08-27 - Monetization: free with in-app purchases - User reviews in markdown: https://appshunter.io/ios/app/audio-kit/id376965050/reviews.md ## What is Audio Kit? Audio Kit is a collection of four tools which are essential for those working in audio, sound and music. A real time Spectrum Analyser, a Scope to display waveforms, an SPL (Sound Pressure Level) Meter, and a Signal Generator producing sine waves, white noise and pink noise. Sweep generation with In App Purchase. 
 -View a real time spectrum of audio with the Spectrum Analyser and identify peak frequencies precisely 
-View the actual waveform of the audio signal with the Scope 
-An SPL Meter provides measurement of sound levels using an A-weighting 
-The Signal Generator provides a sine wave output up to 20,000Hz in 1 Hz steps, along with noise generators for white and pink noise. Sweep generation with In App Purchase ** Spectrum
 ** FFT (Fast Fourier Transform) is used to calculate the frequencies in the Spectrum Analyser and these are displayed in real time. The frequency is displayed in either logarithmic or linear scale. Three FFT sizes of 8192, 4096 and 2048 are selectable, giving fine resolution of frequencies. Interpolation gives resolution to within 1Hz. 
6 different FFT window function types can be selected - Hamming, Hann, Rectangular, Bartlett, Triangular and Blackman. 
 Number of FFT windows can be selected from 1 through 4. The strongest frequency is displayed both above the peak, and optionally, in a large number display in the center of the screen. The large number display can be quickly switched on or off by double tapping the screen.
 There is a screen capture facility in the Spectrum Analyser allowing you to save the spectra for future reference along with details of the FFT parameters, time and date.
 A single tap freezes the screen. Other features such as screen capture and double tap to toggle large number display still work during the freeze. This feature can be turned off in preferences if it’s not desired.
 ** Scope ** The display of the Scope can be adjusted easily using pinch gestures in both horizontal and vertical directions. Zero crossing detection of the waveform provides a smooth display and can be set to either positive or negative direction zero crossing. 

There is a screen capture facility in the Scope allowing you to save waveforms for future reference.
 ** SPL Meter ** 
The SPL Meter continuously displays the sound pressure level using an A-weighting, and has resettable minimum and maximum displays also. SPL Meter can be calibrated against a reference standard or meter. SPL Meter has a continuous ticker style trace of the SPL over time.
 ** Signal Generator ** 
 The Signal Generator has 3 different output types: - Sine wave - White noise - Pink noise 
The output of the Signal Generator can be viewed on the other parts of the App.
 The sine wave frequency selected using picker wheels allows for accurate control of frequency to within 1Hz. Volume for the sine wave and noise signals is continuously adjustable.

 With an In App Purpose one can add a sine wave sweep generator functionality to the Signal Generator. The sweep generator can sweep increasing and decreasing frequencies, and using either a linear or log sweep rate. **Settings
 ** All of the user preferences in each of the above applications can be made persistent between restarts of the App. All parts of the App have direct access to a help document. Audio Kit - essential for those working in audio, sound and music. ## Key features - Real-time Spectrum Analyzer - Waveform Scope - SPL Meter with A-weighting - Signal Generator (Sine, White, Pink Noise) - Sweep Generation (In-App Purchase) - Screen Capture ## Pricing and in-app purchases Base price: $2.99. **One-time purchases** | Purchase | Price | Type | | --- | --- | --- | | Sweep Generator for Audio Kit | $1.99 | one-time | ## Recent user reviews (10 of 38) All indexed reviews: https://appshunter.io/ios/app/audio-kit/id376965050/reviews.md ### 4/5 — Utile *2025-07-19* J’ai acheté pour utiliser le générateur de fréquences qui est, qui semble efficace. Seul bémol c’est que via Bluetooth le son ne passe pas, il faut obligatoirement passer par la sortie casque. Un update serait bienvenu en ce sens. Autrement pas encore utilisé le reste des fonctions, mais il me semble que les notes correspondantes devraient être affiché sur l’analyseur en temps réel et ce serait parfait. ### 1/5 — Mostly useless *2025-06-26, version 2.3* The app hijacked all audio, so I can’t play audio out of the phone other than the audio generated from the app. When it’s in this configuration, I can only measure the sound coming out of the phone, which makes no sense to me. Why would you want a frequency sweep that comes out of the phone only? That doesn’t make any sense. There’s no way to change the audio output as far as I can tell. ### 5/5 — I’ve been waiting for this! *2025-04-12, version 2.3* Simple to use, good features, useful, and I like being able to see a visual representation of what I’m listening to, so I can get a better idea of how the mix sounds through different speakers. This spectrum analyzer is really going to be helpful. Perfect when modding sounds, and seeing how those sounds fit in a mix, especially when looking at how adding, and mixing new bass heavy sounds, affects the definition, and separation, of the final mix. ### 5/5 — Bought this many years ago *2024-12-25, version 2.3* I must get this out of my pocket many times a year due to curiosity - how loud is this, what frequency am I hearing, what does that sound look like on a scope, and it’s always great. I have no idea how much it costs now as I bought it many years ago, but it was so worth it. ### 2/5 — Inflexible Output *2020-10-25, version 2.2.1* It’s very difficult to use over Bluetooth. The app has no settings to select the audio output device and seems to prefer the built-in speaker. ### 4/5 — Please add more FFT sizes *2020-06-25, version 2.2.1* Add 16384 32768 and more fft, for better low frequency resolution. ### 3/5 — Needs updating for iPhone X *2018-02-12, version 2.0* I use this occasionally and it does what it says it does. It needs updating for iPhone X because once you start it there is no way of switching apps or getting back to the home screen other than rebooting the phone. ### 5/5 — Muy útil *2016-11-22, version 2.0* Me gusta mucho esta app. Me gustaría que se pudiera ver el espectro en un rango de frecuencias determinado. Cómo hacer un zoom de una zona. I really like this app. I would like to make zoom in a specific area in the spectrum. Please, updating in that way it will be great. ### 1/5 — Fallo app *2016-11-14, version 2.0* Cuando conectas el mini jack en el móvil e intentas poner ruido rosa a la vez que el FFT SPECTRUM se bloquea y deja de marcar parámetros. ### 4/5 — Hi *2016-08-05, version 2.0* I bought this app last week. Before I used the Lite Version I was very impressed this app so I bought this app! But Full version has a big problem! FFT spectrum Line is not detail even more than Lite version. I want to fix that problem! Thanks! ## Frequently asked questions about Audio Kit ### What does Audio Kit do? Audio Kit is a collection of four essential tools for audio professionals. It includes a real-time Spectrum Analyzer to view frequencies, a Scope to display waveforms, an SPL Meter to measure sound pressure levels, and a Signal Generator for producing sine waves and noise. ### What are the key features of Audio Kit? Key features include a real-time spectrum analyzer with adjustable FFT sizes and window functions, a waveform scope with pinch gesture adjustments, an SPL meter with A-weighting and calibration, and a signal generator capable of producing sine waves, white noise, and pink noise. Screen capture is also available for all tools. ### Is Audio Kit free to use? The core functionality of Audio Kit is free. However, advanced features like sweep generation for the signal generator are available through an in-app purchase. ### What devices is Audio Kit compatible with? The provided description does not specify exact compatibility details. However, as a mobile application, it is designed to run on smartphones and tablets that support its operating system (likely iOS or Android). ### How can I use the Spectrum Analyzer? The Spectrum Analyzer uses FFT to display audio frequencies in real-time, with options for logarithmic or linear scales. You can select different FFT sizes and window functions for fine resolution and analysis. The strongest frequency is displayed prominently, and you can freeze the screen or capture spectra for later reference. ## Version history (last 5 releases) ### 2.3 — 2024-09-27 - Fixed bug with no audio for some devices running iOS 18 or iPadOS 18 - Fixed bug where spectrum fill did not render completely - Slightly expanded spectrum resolution ### 2.2.1 — 2020-05-25 - Fixed bug in sampling for some devices - now giving improved peak resolution - Fixed bug which favoured low end frequencies - Adjusted layouts and behaviours for recent hardware and OS releases ### 2.1.1 — 2018-11-05 - Fixed layout for recent devices and iOS versions - Minor bug fixes ### 2.1 — 2018-11-01 - Fixed layout for and iOS versions - Minor bug fixes ### 2.0 — 2016-04-06 - added availability of in-app purchase for sweep generator capability for Signal generator - reverted to 2 channel output for all Signal Generator outputs. - idle timer can now be disabled if auto lock is enabled on device. This allows user to run the app for long periods unattended without going into lock mode. - minor bug fixes - update for recent iOS releases ## Apps similar to Audio Kit | App | Rating | Price | Category | | --- | --- | --- | --- | | [Sound Decibel Meter-NIOSH,OSHA](https://appshunter.io/ios/app/sound-decibel-meter-nioshosha/id1571075296) | 4.5 (335) | Free | Music | | [Audio / Spectrum Analyzer](https://appshunter.io/ios/app/audio-spectrum-analyzer/id1508848574) | 4.6 (1,013) | Free | Music | | [SNESynth: Chiptune Power!](https://appshunter.io/ios/app/snesynth-chiptune-power/id6455731509) | 4.8 (74) | $4.99 | Music | | [VIRAL Synth 2: T2x \| AUv3](https://appshunter.io/ios/app/viral-synth-2-t2x-auv3/id6749867472) | 4.9 (718) | $7.99 | Music | | [Super J8 Synth + AUv3](https://appshunter.io/ios/app/super-j8-synth-plus-auv3/id6756800933) | 5.0 (81) | $14.99 | Music | | [Pro-A5 Synth + AUv3](https://appshunter.io/ios/app/pro-a5-synth-plus-auv3/id6764386977) | 4.8 (78) | $9.99 | Music | ## More apps by Sinusoid Pty Ltd - [Sonocord](https://appshunter.io/ios/app/sonocord/id871009991) All apps by Sinusoid Pty Ltd: https://appshunter.io/developer/364871696 ## Related topics [sinusoid](https://appshunter.io/ios/topics/sinusoid) --- *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.*