Audio Kit is a collection of four applications which are essential for those working in audio and sound. 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.
-View a real time spectrum of audio with the Spectrum Analyser and identifying peak frequencies
-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.


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.
6 different FFT window function types can be selected - Hamming, Hann, Rectangular, Bartlett, Triangular and Blackman. 

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.


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 both the Spectrum Analyser and the Scope allowing you to save the spectra and 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.


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.


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 - an essential tool for setting up live audio systems.

What's New in This Release:

· fixed Sig Gen sound not being on from clean start when set on in user defaults.
· fixed incorrect unit in scope grid description.
· minor user interface adjustments.

What's New in 1.6:

· Calibration for SPL Meter
· Improved SPL Meter
· Adjusted Signal Generator output volume for newer hardware
· Minor bug fixes and interface improvements

What's New in 1.5:
· Fixed a bug which caused SPL meter to crash in certain cases
· Fixed Signal Generator volume control non-linearity
· Other minor bug fixes
· Note: This will be the last release of Audio Kit supporting iOS 3.0

What's New in 1.4:
· Enhanced frequency calculation improves resolution of maximum peaks to within 1Hz
· Single tap to freeze Spectrum screen. Can be disabled in preferences
· SPL meter has a continuous ticker style trace of the SPL over time
· Improved sine wave generation. Occasionally missed a 1 Hz step in previous version.
· Tested with iOS4.2
· Other minor bugfixes and improvements