MEASUREMENT DIFFERENCE BETWEN MAC AND WINDOWS

[VARON Nicolas]

Hi guys,

I'm Nicolas from Reunion Island.

My problem is that i noticed a kind of low pass filter at around 16khz on the measurements i made with my mac. It does the same to all the speakers that i measure, while most of them are able to go beyond this frequency!
Of course when i take the measurement on my pc the curve remains rather straight. Can you help me please?

Best regards

Nicolas

 

[John Mulcahy]

Make sure the sample rate for the interface is the same in Audio Midi Setup and REW.

 

[VARON Nicolas]

Yes it's the same, I reinstalled REW on my mac but the problem persists ...

 

[John Mulcahy]

Difficult to comment further without seeing mdat files of the same speaker measured from the same mic position with the mac and the PC.

 

[VARON Nicolas]

there are the two captures..

 

[John Mulcahy]

mdat files please, not images.

 

[VARON Nicolas]

Oups

 

[John Mulcahy]

Bit of a mix there of different sweep lengths, different frequency spans and different software versions, the Windows version being particularly old. Make sure the replay and record devices in Audio Midi Setup are both set to a 48 kHz sample format. Probably best to update both Windows and Mac to the current REW build or at least update them both to the 5.19 release.

 

[VARON Nicolas]

I set everything at 48kHz and it is a bit better... i will update REW on the two computers and will give you a feedback. Thanks a lot

 

[sm52]

John, could this be because the data is cut at 20 kHz in the Windows version, and the data is cut at 20 Hz in the Mac version?

 

[John Mulcahy]

That looks a lot better. The remaining 3 dB or so difference at 20 kHz could be due to a roll-off on the replay side of the mac interface.