AFMG Network Forum

hadisumoro · Member

Hello,

I have two questions. The reason I have this question is a need to create etx file (frequency, magnitude and phase) from the polar measurement.

If it helps, this is a quick screenshot: http://www.mediafire.com/?kmfhpbq7r6iqpvu

First question (top picture):
Using the Polar module, is there a possibility to save the files in efr format?

Second question (bottom picture):
I loaded several etm files. How do I re-save all loaded etm files to efr files? Or batch saving the etm files to etx file containing (freq, mag and phase data)?

Thank you.

Hadi

Bruce · Member

Hadi,

It is not possible to save them in efr format in the Polars module. What is the reason that you want to do this?

It is also not possible to save multiple files to a different domain than they currently are in.

Bruce

hadisumoro · Member

Hi Bruce,

Thank you for the answers. I need to create frequency domain etx files from a polar slice. Currently, EASERA does not have a post processing module after a set of polar is taken. While speakerlab can do the job, but it does not provide polar import from -90 to +90deg. Therefore I am creating an excel sheet to post process polar from etx (freq domain) files. So far, I have done the transfer manually (one file by one file from etm to freq domain etx). It takes a lot of time and energy.

Hadi

Bruce · Member

Hi Hadi,

Sorry, I don't understand what you are trying to do. What post-processing are you doing on each slice? SpeakerLab certainly can import -90° to +90° data. What is it that you are measuring?

Bruce

hadisumoro · Member

Hi Bruce,

Oh I did not know Speakerlab does -90 to +90 import. I thought it only imports 0 - 180deg data only (I'm talking parallels, not meridians).

Most loudspeakers measured are under development for crossover and checking the polar (H and V measurement only). First, I need to be able to post process a quick H and V only of a loudspeaker, but only from left to right (-90 to +90, I'm sorry if my way of numbering the angles are not clear).

Secondly, the data needs to be transferred to LEAP in etx (frequency domain) data. So far, I have done this by saving each etm file to etx (freq) one by one, manually.

Measurements are often performed for xover development, driver position/alignment and horn development. A lot of time, data is not taken at 90 - 180 (back radiation), but only the front radiation (left and right of loudspeaker front).

Let's say there is a (slice) polar data set (37 files, 5deg resolution) as named:
IR270, IR275, IR280, ... ,IR085, IR090 or

IR-090, IR-085, IR-080, ... , IR085, IR090

How do you post process this in speakerlab?

Hadi

hadisumoro · Member

For the LEAP data transfer, I forget to mention that the data is expected at -90 to +90 (left to right, or up to down, no back radiation).

Bruce · Member

Hadi,

Ah, thank you very much, now I understand what you are trying to do.

First, in EASERA Polars you can do just a polars measurement of the front half by setting your loops up correctly. In my case, I started with the Full Circle Polar Measurement, set the outer loop to 4 measurements at 90° increments, and the inner loop to 19 measurements at 5° increments. Adjust these as necessary for your setup. Total of 76 measurements. Then Save that so it is easy to load in for the next time.

These can be imported in SpeakerLab by selecting the option Front Half Only under Parallels. Meridians is then set to Full Symmetry and 90° (Polars), and Parallels for 5°.

With regards to the transfer for LEAP, I will enter a feature request to allow saving to ETX Frequency Domain to the EASERA Dev Team. At this point, you would need to do the Time-Freq transformation in Excel using the Time ETX files saved from EASERA as a post-process.

Best regards,
Bruce

hadisumoro · Member

Hi Bruce,

I apologize I was not clear before. I will do your method. It does make sense. Thank you for your quick reply and support.

Hadi