Analysis VPI's  -  SpectroGraph

SpectroGraph is a tool to clearly identify disturbances with continuous frequencies in audio signals, such as mains hum, pilot tones in broadcast signals, DC offset, etc.

It is very useful in finding frequency characteristics of instruments and harmonics, or to visualize the spectrum of a noise floor. The frequency range from 'zero' to 'half the sampling rate' of the incoming signal is displayed in a spectrogram.

The display consists of sixty four colors with very fine frequency resolution, over a three second period. By moving the mouse over the spectrogram, the frequency, level, and time of this point are shown in three individual displays, providing a visual reference for frequency identification. Two sliders set the range of the levels to be displayed. Signals above and below those levels will not be shown, providing a better focus on the level of the target frequency.

The frequency range can be limited to 1 kHz for a more in depth analysis of the lower frequency range. Left or right channel of stereo material can be viewed, and in stereo mode the sum of the spectra of both channels will be shown, avoiding cancellation effects caused by phase inverted channels.

The SpectroGraph is part of the Cube-Tec Analyzer package , a family of real-time visualizing analysis tools that include: PhaseScope , ZoomAnalyzer and MatrixScope.