No Impulse results when using averaged results

[AnthonyLoFi]

Hi All,
I am using V5 20.13 on a macbookpro Intel.
I have no problem recording both left and right SPL frequency response graphs.
The measurement records both SPL and Phase.
When I then view the Impulse results I get a full display of information.
I am wanting to rectify frequency alignment etc so was expecting to see a far different result which other guides show is a single waveform.
If I go to the EQ tab and display the Impulse from that screen I get the anticipated waveform.

I believe I need that simpler waveform on the main screen to perform many other functions but for the life of me can not figure out what I have done wrong?


Also can you help with the second question.
Averaged Results
When I average a number of measurements, the average measurement will then remove the Phase information.
When I click on the Impulse tab from the All SPL tab, the screen shows no results?
Also the IR Window has all information greyed out in both SPL & Phase and All SPL screens.
Where I am using an average of many measurements taken sequentially to find an accurate mean, I will then need the Phase information hence my question.

Do I have to create or manually generate the Phase information for each measurement by using in the Control window, Generate minimum phase?

I hope its something stupid I have missed. REW is such a huge scientific program that when using, one must double check every step of the measurement parameters and setting to ensure the correct outcome is achieved.
The results are only as good as the person behind the keyboard.

 

[AnthonyLoFi]

UPDATE
I believe I have found my mistake to not be able to view Impulse curves by the incorrect display click box in the upper left hand screen area of the wave form display.
Its not easy to see it.
You have two drop down menu choices (%) or (dBFS), its % and then you can display it.

I still haven't worked out how to create Phase information from averaged measurements.

 

[John Mulcahy]

Magnitude averages do not have phase information and so do not have an impulse response. The vector average includes phase and produces an impulse response, but it must be used with care - phase differences in parts of the measurement will cause dips or notches in the average. Those can be minimised by aligning the responses to be measured using the Cross corr align feature of the 5.20.14 early access build. That build also has two options to produce RMS and dB averages that have phase data from a vector average, but the corresponding impulse response will often look odd as a system with vector phase and RMS or dB averaged magnitude is not physically realisable and will have significant content before t=0.

 

[AnthonyLoFi]

Thank you John,
"Magnitude averages do not have phase information and so do not have an impulse response."
Ok, thats logical and understand how the software can only accurately calculate of real world knowns.

The vector average includes phase and produces an impulse response, but it must be used with care - phase differences in parts of the measurement will cause dips or notches in the average. Those can be minimised by aligning the responses to be measured using the Cross corr align feature of the 5.20.14 early access build.
Great, you are continually finding new additional ways to produce audio information for understanding audio wave forms. I am not anywhere near competent to use high order manipulation facilities the next version has so will be limiting myself with V 13.

That build also has two options to produce RMS and dB averages that have phase data from a vector average, but the corresponding impulse response will often look odd as a system with vector phase and RMS or dB averaged magnitude is not physically realisable and will have significant content before t=0.
Ok I know my limits and will a take your advice on that. This information will help those that are far more advanced.