Thank you for your response and sorry for the late reply but I am currently dealing with a broken leg…:(
I have performed the additional test you describe in your 2nd post bu only 2a.
I have simulated 3 x 12 octave chirps ending at Nyquist (taking the start freq. from the calcs in ExpoChirp).
For 2b it is not clear to me which type of fade I should apply to the resultant IR.
Do you mean fading the resultant IR in time of freq domain?
If in time domain how long would you like the fade to be?
if in freq. domain, which freq. should be faded?
Please have a look at the screenshot attached.
I have sent you an email to your private adress as well.
Speak to you soon