- Create an exponential sine sweep of uniform amplitude

- You may create the sweep in SHAART by clicking on the "Equation" tab and leaving the default equation text in place and selecting "Go". (The default is for a 10 second sweep from 20 Hz to 20000 Hz.)

0.8 * sin( 20 *2*PI*TMAX/ln(20000.0/20) * (exp(t/TMAX*ln(20000.0/20))-1) )

- Alternatively you may generate one in Audacity by selecting Generate > Chirp and then "Logarithmic". Be sure to set the starting and ending amplitudes to be the same.

- Play the sweep from your speaker while recording the response. (SHAART does not currently have recording functions). Save the response to a WAV file.

- In SHAART, choose "Equation" and this time copy & paste in the "Inverse Exponential Sine Sweep" equation text...

exp(ln(20000.0/20)*(-t)/TMAX) * sin( 20 *2*PI*TMAX/ln(20000.0/20) * (exp((TMAX-t)/TMAX*ln(20000.0/20))-1) )

...and press Go. This will go into "File A" in SHAART.

- Load the response WAV file into "File B" in SHAART.

A comparison of the two files now in memory will look like this:

- Go to the "Convolve" tab and simply press "Go". (No other instructions or actions are necessary. Do not time-reverse file A).

- File A now contains your Impulse Response!

Referencess:

Farina: http://aurora-plugins.forumfree.it/?t=53443032

Inv Exp Sweep: http://kc.koncon.nl/staff/pabon/IRM/IRMeasurementInstruction/assignment_IR_ExpSweepTheory.htm