Oscilloscope vs Audio / Spectrum Analyzer

"I use this for analog, and audio measurements. Attach an Apple USB adapter and a $40 stereo A-D converter available online, and my iPad is like a $300 O'Scope." -thymeout- Oscilloscope app is great for analyzing audio range signals, or learning oscilloscope measurement basics. The interface includes many standard oscilloscope controls, such as: triggering, time and voltage per division, signal measurement cursors, and more. The app incorporates a signal (function) generator capable of generating sine, square, triangle, and sawtooth waveforms of up to 22 KHz. Calibration to an external reference signal is supported, guaranteeing the accuracy of measurements. Input can be acquired via the built-in microphone or an external mic/probe connected to the headset connector. For best results, use an external audio interface connected to your device dock. This allows for standard audio equipment to be connected, as well as for dual channel input. Oscilloscope probes also be connected (using a BNC connector). When feeding external signals via probes, you should take care not to exceed 1V AC voltage. Currently iDevices support only AC input. For up-to-date information on feeding signals and currently supported audio interfaces, please visit http://oa.onyx3.com Feature Highlights: ● Real-time waveform display (60 FPS) ● Triggering modes: Normal, Auto, Single ● Set trigger level and pre-trigger time ● Dual channel signal generator ● Reference signal calibration ● Pause function to get a screen capture ● Export traces as text file for further analysis ● Measure signal data using cursors ● Use "finger pinch" on screen to set voltage and time base ● Double tap screen to enter Black Panel mode ● Three color themes to choose from ● XY mode for viewing Lissajous figures ● Frequency range 20Hz-22KHz ● iPhone X ready

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).