HOLMImpulse: Measuring Frequency & Impulse Response

Hello,


I need some advice or a tip:


I've bought a cheap measurement mic (Superlux E888B) and had it calibrated.


Now, that I've imported the calbration file into HolmImpulse, the measurement graph of a previous (uncalibrated) measurement did not change. I'm quite sure the cal-file has the correct syntax.


Do I have to measure with an already imported cal-file to get a corrected graph?
IOW: Does HOIP correct older measurements?


Can I see the cal-file's effect when ticking/unticking the respective option?


Is there any other option to verify that the cal-file has been loaded - e. g. an ini-file or a registry setting?


Thanks and kind regards
 
Just another Moderator
Joined 2003
Paid Member
The cal file as far as I know will only adjust measurements done when the cal file is loaded, it doesn't apply it to already taken measurements.

If you want to correct an existing measurement you can load the cal file as a standard FR and subtract it (using the divide function) from the measurement.

This is assuming that the cal file shows the microphpones response, as opposed to what corrections would be needed to make it flat (I believe that is the norm).

Tony.
 
I have made a loopback measurement and the result is pretty clear.


Unticking the calibration file option results in an uncorrected measurement
while ticking the option will apply the correction parameters to the measurement.


One can do that under section measurements ad libitum to specified measurements A to C.


But, once a measurement has been completed it cannot be changed (corrected) by changing the cal-file option.
 
Just another Moderator
Joined 2003
Paid Member
Cool so now you can get an uncorrected loopback and divide it by the cal file and what you should get is something identical to the loopback with cal file in play.

If that works then you should be able to do the same to existing measurements that were taken without the cal file :)

Tony.
 
Yes.


you've gotten something like this from an older uncorrected measurement:


20Hz______________________--------20KHz


Your calibrated loopback results in this:


20Hz-------------------------------______20KHz


Now you have to combine these graphs using the correct math operation to get the old measurement corrected.


May be substraction.
 
Hi,
I discovered this software reading through Geddes website. I was on the way to try it, but how on earth do you start a logsweep with it ??? I see no button/menu item for that :adjustments, yes, but no start button... I tried the "save" buttons with no success (ASIO connexion to SC choosed)
I wondered if it shows only if calibration files are chosen ?
 
Are you in contact with Ask? He might have a good idea of what is possible there.


Companies take code that they no longer want to develop and "open source" it all the time. I was IBM's "open source" counsel for 17 years and we did this at least a couple of times a year and my opensource colleague's at other (big) companies often had to clear such software for open source distribution as well. Sometimes the opened code garnered a lot of support, sometimes there was zero interest. But it was almost always good for relations with the various open source communities.



Does someone have a contact at Holm? As they say there is no harm is asking.


Terry
 
Well then Terry, you'd be the logical choice to contact them about it! :)

I am flattered by the suggestion and would if I could, but except for pro bono work, I can’t provide counsel to anyone except my employer. (This is typical for all corporate attorneys).

More importantly, 17 years of experience with OSS developers has taught me that they DON’T WANT TO HEAR FROM LAWYERS! Particularly other party’s lawyers. I have always encouraged developer to developer dialogs. It just works so much better.

Now if you want to learn generally about the different OSS licenses I can do that.

So although I am a big fan of Holmimpulse, I have to decline.
 
Just a quick OT question: why obsolete HOLMImpulse and not ARTA? Is 80€ license too much or is there some "actual" issue(s)?
Alternative tool with more flexible and visual UI for converting ARTA pir-files (and CLIO mls-files) to FRDs is available in VituixCAD, though that won't make ARTA freeware or improve support on other platforms than Windows.