Real-time 3D Spectrogram (Advanced Feature): Spectrogram data can be plotted as a 3D surface or mesh in real time. Rotation and zoom are supported through touch gestures (trackball-style single-finger drag and two-finger pinch, respectively) even while the spectrogram is running.
User-friendly Frequencies: Traditional FFT-based spectrum analyzers use FFT's (Fast Fourier Transforms) with lengths that are powers of 2 (e.g. 2 to the 12th power = 4096). With typical audio sample rates, such as 48 kHz, this yields non-integer (awkward) frequency resolutions, such as 11.71875 Hz (48000/4096 = 11.71875). SignalScope's FFT Analyzer uses mixed-radix FFT's that yield frequency resolutions that are more than just user-friendly—they allow for precise amplitude measurement at frequencies such as 1000 Hz (a frequency commonly used for calibrating sound level meters and measuring total harmonic distortion, or THD). For example, an FFT length of 4800, when used with a sample rate of 48 kHz, yields a frequency resolution of exactly 10 Hz (48000/4800 = 10).
Save Data: Export spectrum magnitude values and metadata to a data file (.csv, .mat, or .txt). Or, generate a high-resolution image of the graph and save it to a PDF file.
Input: 1 channel at a time, selected from any available input, output, or virtual output channels
FFT Type: Mixed Radix
Frequency Resolution (Hz), per sample rate:
Built-in Accelerometer (iPhone and iPad), 100 Hz
10, 5, 2, 1
50, 40, 20, 16, 10, 8, 5, 4, 2, 1
50, 10, 5, 2, 1
50, 10, 5, 4, 2, 1
50, 10, 8, 5, 4, 2, 1
All other sample rates
50, 40, 32, 20, 16, 10, 8, 5, 4, 2, 1
FFT Length: Set automatically, based on frequency resolution and current sample rate (e.g. at 48 kHz, a frequency resolution of 5 Hz requires an FFT length of 9600 points)