Audio / Spectrum Analyzer

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 (4 types of waveform)

- Pitch meter display.

The Pro version offers Ad-Free Viewing and High-Resolution Analysis (FFT size: 16384/32768, Sampling Rate: 96k/192k, Spectrum Average: 4, 8).

[Setting items]

[1. View Type]

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. Sampling Rate]

Select sampling rate.

32k, 44.1k, 48k, 96k, 192k[Hz] (* '96k,192k' are available in the Pro version.)

The spectrum frequency range is set according to the sampling rate (up to the Nyquist frequency).

[3-1. FFT Size]

1024, 2048, 4096, 8192, 16384, 32768 (* '16384, 32768' are available in the Pro version.)

[3-2. Window Function]

Select the window function (multiplied immediately before performing the FFT).

- Hann: Hanning window

- Hamm: Hamming window

- Blkman: Blackman window

- None: No window function

[4. Spectrum Average (N Ave)]

Number of spectrum average for a display of spectrum. (init value: 1) (1, 2, 4, 8) (* '4, 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]

Select the frequency weighting. (Used when measuring sound pressure level with a sound level meter.)

- Flat (Z-weighting): No frequency weighting.

- A-weighting: Frequency response that takes into account human hearing.

- C-weighting: Relatively flat response that covers a wider frequency range than A-weighting.

[7. Peak Hold]

When ON is selected, displays the results of holding the past maximum values (peak values) of the spectrum.

[8. Octave Analysis]

Set the spectrum to be divided into octave bands.

Division method:

- FFT: Spectral display (conventional method)

- 1/12, 1/6, 1/3, 1 octave: Display divided into octave bands (the larger the value, the larger the band width)

Calculation method:

- Max: Displays the maximum spectrum value in each band

- Average: Displays the average spectrum value in each band

[9. Frequency Axis Scale Type]

Select how the X-axis (frequency) of the spectrum is represented.

- Linear: Distributed at equal intervals

- Log: The intervals increase logarithmically

[10. 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.

[Other]

- Background color: Black, White

- WaveForm: Line Color (Green, Yellow, Invert), Line Width (1.0 ~ 5.0 px)

- Spectrum: Bar color (Green, Yellow, Color patterns)

- Spectrogram: Colormap, Display range (-150 ~ -60 dB), Display time (4 ~ 60 sec), Apply Spectrum Tilt

- Scaling of Waveform display in the X or Y direction.

- Scaling of Spectrum / Spectrogram display in the X direction.