Audio Kit vs Audio / Spectrum Analyzer

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.

This RTA app supports simultaneous display of "Audio Waveform", as well as the FFT-based "Amplitude Spectrum" (frequency magnitude) and "Spectrogram" (frequency distribution over time), for audio signals input from a microphone. (FFT: Fast Fourier Transform, RTA: Real Time Analyzer) [Features] - Supports simultaneous display of Waveform / Spectrum / Spectrogram - Supports orientation both portrait and landscape - FFT size - Window function - Spectrum average - Spectrum Tilt - Frequency weighting (Flat, dBA, dBC) - The type of expressing the frequency of Spectrum / Spectrogram (Linear, Log) - Displays the peak level and its frequency of the spectrum - Peak Hold (displays the results of holding past peak values ​​of the spectrum) - Octave Analysis (displays the spectrum divided into octave bands) - Generates the audio signal (Sine, Triangle, Squire, Saw) - Generates the noise signal (white noise, pink noise) - Pitch meter display The Pro version offers Ad-Free Viewing and High-Resolution Analysis (FFT size: 16384, 32768, Spectrum Average: 4, 8). [Setting items] 1. Screen structure : Select the display screen configuration. View Num : 1, 2 View Type : - 1 screen : Wave (Waveform) / 1D (Spectrum) / 2D (Spectrogram) - 2 screens : W+1D / W+2D / 1D+2D Layout : Vertical / Horizon 2. Frequency Axis Scale Type : Selectable the type of expressing the X direction (frequency) of Spectrum / Spectrogram. - Linear: Distributed at equal intervals - Log: The intervals increase logarithmically 3-1. FFT size : 1024, 2048, 4096, 8192, 16384, 32768 (* 16384, 32768 is available in the Pro version.) 3-2. Window function : Hanning, Hamming, Blackman, No window 4. Spectrum Average Number of spectrum average for a display of spectrum. 1, 2, 4, 8 (init value: 1) (* 4 and 8 are available in the Pro version.) Higher value will make the spectrum less noisy and more smooth, at the cost of lower time resolution. 5. Spectrum Tilt : Compensates the visual slope of the spectrum around a 1 kHz pivot. -6.0 to +6.0 dB/oct in 0.5 dB/oct steps (0 means no tilt). 6. Frequency Weighting : Selectable frequency weighting. - Flat: No frequency weighting is applied. - dB(A): Frequency response that takes into account human hearing. - dB(C): Relatively flat response. 7. Peak Hold : Displays the results of holding the past maximum values ​​(peak values) of the spectrum. 8. Octave Analysis : Displays the results of classifying the spectrum into octave bands. Division method: - FFT: Spectral display - 1/24, 1/12, 1/6, 1/3, 1 octave: Display divided into octave bands Calc method: - Max: Displays the maximum spectrum value in each band - Average: Displays the average spectrum value in each band 9. Generates the audio signal : Set the audio signal to be generated. - There are 4 types of waveform. (Sine, Triangle, Squire, Saw) - It can set the value of the frequency in 20Hz - 20000Hz. 10. Generates the noise signal : Set the noise signal to be generated. - There are 2 types of noise. (White noise, pink noise) [Other] - Background color: Black, White - WaveForm: Line Color (Green, Yellow, Invert), Line Width (1.0 ~ 6.0 px) - Spectrum: Bar color (Green, Yellow, Color patterns) - Spectrogram: Colormap, Display range (-150 ~ -60 dB), Display time (4 ~ 60 sec), Apply Spectrum Tilt - Bluetooth connection policy selection (disabled, HFP, A2DP). - Scaling of Waveform / Spectrum display in the Y direction (magnification: 0.5 - 2.0). - Scaling of Spectrum / Spectrogram display in the X direction (magnification: 1.0 - 16.0).