Averager : Average

Here the averaging process can be tweaked and the result viewed in real-time.

Reference Controls

The Reference checkbox turns on/off the display of the Reference measurement.

The drop-down is used to select the Reference measurement. The result is the same as selecting the Reference on the table on the Load tab.

Delay (samples) Here the Reference measurement delay can be adjusted, in quarter sample increments (at the Sample rate from the Load tab). Any change to this delay is also applied to all other measurements.
+ and – These buttons increment and decrement the Reference measurement delay in quarter sample increments (at the Sample rate from the Load tab). All other measurements are also moved by the same amount.
Move IR peak to 0 This button moves the peak in the Reference measurement impulse response to time=0 (by setting the “Apply common delay (ms)” setting, on the Load tab, to the negative of the “Ref peak delay”). All other measurements are moved by the same amount.
Invert If this is checked, the Reference measurement is inverted, prior to averaging. When changed, the polarities of all Comparison measurements are toggled to maintain their relative polarity to the Reference measurement.

Time Align all to Reference

This button will automatically adjust the delay of all comparison measurements so that their impulse responses are aligned with the reference measurement. This performs the same function as the Time Align all to Reference button on the Load tab.

Comparison Controls

The Comparison checkbox turns on/off the display of the Comparison measurement. The ▲ and ▼ buttons select the previous or next Comparison measurement.

The drop-down is used to select the Comparison measurement.

Use This denotes whether the measurement is used when calculating the average measurement. Unchecking “use” will remove the measurement from the averaging.
Delay (samples) Here the Comparison measurement delay can be adjusted, in quarter sample increments (at the Sample rate from the Load tab).
+ and – These buttons increment and decrement the Comparison measurement delay in quarter sample increments (at the Sample rate from the Load tab).
Averaging weight The shows the weight multiplier applied to the measurement during the averaging. 1.0 is equivalent to using 100% of the measurement data. See the section on Averaging Modes for notes on exactly how the weight is used in each mode.
Invert If this is checked, the Comparison measurement is inverted, prior to averaging.

Averaging Mode

Complex

This mode performs complex averaging of the measurements. This may result in loss of energy in frequency regions where phase is not consistent across the measurements.

The averaging weights are applied to the complex data and the average is normalised by the sum of the weights.

Power (flat, zero phase)

This mode performs a power average of the measurements. The phase of the average measurement is set to zero degrees.

The averaging weights are applied to the power of each measurement and the average power is normalised by the sum of the weights.

Power (minimum phase)

This mode performs a power average of the measurements. The minimum phase response is then calculated from the magnitude of the average response.

The averaging weights are applied to the power of each measurement and the average power is normalised by the sum of the weights.

Power (min. phase + Ref. excess phase)

This mode performs a power average of the measurements. The minimum phase response is then calculated from the magnitude of the average response. Also the excess phase of the Reference measurement is calculated and added to the average measurement phase.

The averaging weights are applied to the power of each measurement and the average power is normalised by the sum of the weights.

Power (with complex avg. excess phase)

This mode performs both a power average and a complex average of the measurements. The excess phase of the complex average is combined with the magnitude from the power average to create the average measurement.

The averaging weights are applied to both the complex data and the power of each measurement and both the complex average and power average are normalised by the sum of the weights.

This mode can be useful for removing excess phase from a loudspeaker and maintaining only the minimum phase response. This can be achieved by loading this averaging into FIR Designer or FIR creator and designing FIR filtering to flatten the phase.