message error when calibrating impedance

[oliver]

hello John,
I do have this error message when calibrating the impedance measurement:

I am on OSX 10.13.6, latest REW build release.
This error is dispalyed with every calibrating method.
Attached also all what inside the log folder.
Oliver.

 

[John Mulcahy]

Hi Oliver, there are two possible fixes:

- Use a shorter sweep for calibration
- Edit the .zma files in the logs folder and remove the lines with frequencies less than 0.15 Hz

I will work on a fix in the meantime.

 

[oliver]

Hi John,
thanks for the prompt reply.
I have deleted the preferences and done a clean install however.
just few small things.
I have performed a Reference cal, after that it is normal that the input impedance of the audio card has disappeared?

On the impedance graph, the two zoom buttons could be moved? They cover the measurement and is quite hard to see the curve underneat

It happened few times that REW freezed during an impedance measurement, the measurement bar was close to the end but then it stopped, and I had to forcefully close it.
Thank you.
Oliver

 

[John Mulcahy]

I have performed a Reference cal, after that it is normal that the input impedance of the audio card has disappeared?

Yes, that value is no longer used after a reference calibration, that is also mentioned in the help. Have you done the short circuit cal? Rleads should not be visible after the short circuit cal. The steps should be done in order, open circuit then short circuit then reference.

On the impedance graph, the two zoom buttons could be moved? They cover the measurement and is quite hard to see the curve underneat

The buttons only appear when the mouse is over the graph.

It happened few times that REW freezed during an impedance measurement, the measurement bar was close to the end but then it stopped, and I had to forcefully close it.

Can you attach the log files, please. What was the message above the progress bar when it stopped? How long did you wait?

 

[oliver]

Yes, that value is no longer used after a reference calibration, that is also mentioned in the help. Have you done the short circuit cal? Rleads should not be visible after the short circuit cal. The steps should be done in order, open circuit then short circuit then reference.

Hi John, yes, after the short circuit cal Rleads is no more present.
Attached the three cal steps.


The buttons only appear when the mouse is over the graph.

Yes, but if you try to follow the curve with the mouse to highlight any problem in those frequencies, it becomes difficult.

Can you attach the log files, please. What was the message above the progress bar when it stopped? How long did you wait?

I wait around 40 seconds, there was no message, the progress bar was just not moving and when I closed the "make a measurement" window REW become kind of shaded white and not responsive.

Here the logs, although I think the problem occurred before the reinstallation, so probably not present in this log.

I was also removing all the traces from an usaved file and had the java error attached.

 

[oliver]

Hi John,
after performing all the calibration steps I have performed a measurement, and even if in the "make a measurement" window I can see the correct impedance curve as in this picture:

I ended with a 4.7Ω straigth line as in the Reference cal step.
Attached the measurement file and the logs.

 

[John Mulcahy]

Your short circuit calibration looks like it was actually an open circuit calibration, did you short the test leads together?

 

[oliver]

Hi John,
sorry, my fault.
I have performed again the impedance cal, it seems now is correct.

 

[John Mulcahy]

The short circuit impedance looks very high, and has an odd kink at 10 kHz.

For the measurement it seems a little unusual that the impedance from 4k - 10k is below the LF impedance, is that expected?

 

[oliver]

Hi John,
I do have a tool box with switches in order to select the measure and the ampli according to what I am measuring.
I have bypassed the box and repeated the calibration without the tool box, only the minumum jig needed for impedance measurement.
Attached the result, that is around 1.6Ω. The small spike at 50Hz and 150Hz is due to a bit of noise in the electricity supply of my area.

Regarding the Impedance curve, that one is from a Balanced Armature micro driver that is quite inductive, so it is what expected.