App: system-eye
Developer: Naumenko Oleg
Genres: Music, Productivity

System-eye is a dual - channel FFT audio analyser suited for live audio engineers. It allows you to measure the Transfer Function of the sound system under test, in real time, by comparison of reference signal and signal produced by sending the reference through system under test, so called, measurement signal, in frequency domain.

It was designed to be very simple and lightweight, supplying the core needs of experienced system engineer, without an overkill of well - known alternatives.

It supports one measurement channel pair at a time, and so far cannot do such advanced stuff as Live average. It doesn't do SPL/calibration whatsoever.

What is does is Transfer Function (Frequency Response) part. Including coherence for measurement validity assessment, IR graph to see time data, and a set of averaging and smoothing capabilities to get You understanding your system in minutes.

Audio Input connection

Use external auido interface, input 1 - measurement mic, input 2 - reference signal. Select correct audio interface in Preferences; Send the same reference signal to input 2 and to measured system (use wire split). Use level indicator in the left bottom corner to make sure you get two distinct signals on reference and measurement channels.

AutoDelay

Use AutioDelay button to turn on automatical delay detection between mic and reference. Without proper delay detection the measurement will be incorrect. Once you capture a trace of your measurement, Delta Delay reading becomes visible.

System-eye is equipped with pink noise generator that can be used as a reference signal.

Captured traces

You can capture traces of Your measurement for future reference. Traces are stored in Trace Manager. You can open Trace manager using T keystroke, or using menu View -> Trace Manager. You can hide/show traces, change name and color and delete them.

Signal Generator

You can use built-in signal generator to generate pink noise as a stimulus for measurement. Use G keystroke to toggle it on /off. Go to settings to adjust level and destination output device.

Start/stop analysis using S keystroke, L to show/hide live trace, I, P and C to show/hide Impulse response, Phase and Coherence plots respectively.

And don't forget to have fun!

Release notes:
v.1.3:
- maintenance update, fixed crash and improved stability diagnostics

v.1.2:
- fixed color of live trace cell when it is selected and Mac is in light theme
- fixed Auto Delay button appearance for El Capitan

v.1.1: 
- Added Generator switch in main window
- All graphs are labeled for convenience
- Separate Coherence graph
- Phase, Coherence and IR graphs now can be hidden independently
- Improved Phase graph - scrollable phase plot, "true wrapped" phase smoothing is used
- Improved "Overlap scales" graph mode
- Convenient keystrokes for basic functionality (G instead of cmd+G, e t.c.)
- Improved Auto Delay - faster and more stable
- Better delay manual input field behaviour 
- Current X and Y ranges for all plots are saved and restored on start
- Added trace CSV export (right-click on a trace in a Trace Manager)
- Selected traces now appears frontmost in the graphs
- Cursor now follows any selected trace, not just live trace
- Trace selection is possible by clicking on the graph, trace has to be visible (not hidden)
- Removed rough 1 and 1/2 oct smoothing modes
- Re-visited time averaging that results in more stable readings
- Added imperial distance units (Should pick your standard automatically, Prefs->Appearance to change manually)
- Improved noise generator - removed unnecessary filtering.
- Fixed crash when switching between stored traces fast
- Fixed input meter response 
- Fixed IR graph not updating under certain conditions
- Fixed black holes instead of labels on scales when moving to another screen, or, sometimes even on app start
- Added hidden coherence threshold adjustment for blanking (press cmd and hover mouse over Coherence plot)
- Should support new M1 CPU architecture
- Huge improvement in CPU & Energy usage due to many calculation optimisations
- Improved appearance && usability