Input Signal Analyzer (ISA) & Input EQ
With the introduction of the ACO platform, all DSP devices have been given the opportunity to analyze the amplitude response of the signal source that is connected to the analog inputs
1. Opening the ISA menuISA can be accessed via the menu item „IO“ by selecting the sub-item of the „Input EQ“:
This feature is integrated in the user interface of the „Input EQ“ and can be adjusted via the control elements positioned below the graph.
2. Operation of the ISAVia "drag & drop" you select the channel to be measured or form a sum of several channels. Just like in the “IO menu“, the mixing ratio can be adjusted with a double click.
The main difference compared to the normal IO configuration is that this "drag & drop" feature does not define a DSP channel, but the input signal of the analysis tool.
The ISA measurement starts with a click on the "Start" button and is automatically stopped whenever the signal summation or other parameters are changed.
The progress of the measurement is shown on the progress bar. This bar graph runs through once before a first result is displayed – then the measured amplitude response is continuously updated as long as the measurement is running.
If an ideal mixing ratio has been found when analyzing a sum of several channels (e.g. the high frequency and low frequency signal of an OEM amplifier), this setting can be transferred to any channel of the “Main Routing” with the “Transfer Routing for:” button .
In order to perform a more precise measurement in a certain frequency range, the bandwidth of the measuring range can be refined by switching the “Measurement preset”.
The fullrange measurement gives the best overview of the entire frequency band when summing high- and lowpass filtered signals.
If you like to detect with ISA a highpass or allpass filter especially in the low-frequency range, it makes sense to select the “Low” measurement range in order to increase the resolution of the measurement.
The measurement method works with „correlated pink noise“. It is important to only use this signal for the analysis – otherwise readings of channel summations and other analysis methods will not work properly and lead to incorrect measurement results.