REW Beta Release REW V 5.20 Beta 13 64 installer

[CAAudiophile]

I am using the latest REW V5.20 beta 13 64bit Install. I could not generate the Minimum phase after taking the F R of a speaker/driver I tried to use older version of REW the same issue ... even if I go way old not sure if I have to delete all version of REW on my laptop in order to use the old version, but that is not the question. The question is why certain measurement the Minimum Phase is generated and others are not.

Here are the steps of what I am doing to generate the minimum phase:

1- Take a frequency response of a driver (woofer and then Tweeter)
2- From main screen go to ALL SPL tab (second tab)
3- Select/ click on the Controls icon
4- select the curve name
5- Click on the "Minimum Phase Version" button
Result:
For the woofer the minimum Phase curve is displayed.
For the tweeter when I click on the Minimum phase curve button, nothing is displayed .. however the short message displayed at the bottom saying "Calculating" but nothing was displayed even if I wait 15 minutes.



Please advise, knowing that I was able to do so in pervious versions of REW 18 and older.

 

[John Mulcahy]

I am using the latest REW V5.20 beta 13 64bit Install. I could not generate the Minimum phase after taking the F R of a speaker/driver

Thanks for the report, please attach an mdat file that shows the problem.

 

[CAAudiophile]

John, thank you for the prompt response to the issue. The problem was not selecting the proper Timing Reference in the measurement window . i.e The loopback timing reference was not selected before taking the frequency response of a driver. There is a new dropdown menu box... It must be a one of the new features that been added to the measurement window, (great idea). Perhaps an error message should be displayed stating to select the proper Timing Reference. just an idea.

What is the Time Align button does?


Thank again for all the improvements.

 

[John Mulcahy]

I'd still like to see a file please, the timing selection should have no influence on whether minimum phase generation works.

Time align is explained in the All SPL graph help.

 

[CAAudiophile]

Hi John,
I tried to duplicate the problem by taking the FR of a tweeter without a loopback timing as a reference but unfortunately I was able to produce a Minimum Phase curve for the file. I could not reproduce the issue.!
The other question(s):
How to make a STEP response curve? shouldn't a square wave be used to have a step response?
If so how do you do STEP Response curve using a square wave?
Now I get the step response by having a FR of a driver and by selecting the Overlay window/ Step tab.


Regards,
Sam

 

[John Mulcahy]

Step response is the integral of the impulse response, there is a step response trace available for selection on the Impulse graph.

If you look in the REW log files you may find some error info from then the min phase wouldn't generate. The files are in a directory called REW in your home directory, can just zip that whole directory and attach it here and I can check the files to see if anything was captured.

 

[CAAudiophile]

The REW dir was zipped, please find it attached.
If I wish to use a square wave as a signal to create the Step Response is there a way to do that in REW?
The square wave will simulate a gun shot or a balloon pop sound for time alignment.


Regards,

 

[CAAudiophile]

John, Not sure if I could attach the zip file ... I tried in the above message ... but it doesn't look like it was attached?

 

[John Mulcahy]

Don't see it, you can email it to feedback@roomeqwizard.com.

 

[John Mulcahy]

A gun shot or balloon pop are approximations to an impulse. If you want to capture a step response manually you could use a recording utility and a low frequency square wave, but it won't look any different to the step response REW shows you.

 

[CAAudiophile]

The zip dir was sent via the email provided.
Please share the finding if any ..

Thanks John in advance.

 

[John Mulcahy]

Wrong directory, I was looking for the REW directory that is in C:\users\<your username>. The location is also shown in the About REW dialog.