Max 20dB calibration limit?

[vittorio]

Dear All,

I have looked into REW seriously for the first time today and I absolutely love it. However I found something I don't quite understand. I took a function generator to make a manual calibration of the input of my soundcard only (so not the whole loopback), with some patience I got a reasonably well detailed curve, which in some points (very low or very high frequencies) needs >20dB compensation to have a flat response. I found though that REW doesn't seem to allow calibration values lower than -20dB. Anything below -20dB in the calibration file will simply be clipped to -20. Is this an intended behavior or is it unexpected?

I can actually live with it now that I am aware of it, but it would be nice to have some extra freedom I suppose...

 

[John Mulcahy]

It is an option in the Frequency Response Calculation part of the Analysis preferences:

If Limit cal data boost to 20 dB is selected REW will limit the total gain applied to compensate for calibration data attenuation to 20 dB. This prevents excessive boosting of the noise floor in areas where the combined mic/meter and soundcard response is more than 20 dB down. This setting affects the frequency response, RTA trace and SPL meter readings and is also applied when carrying out trace arithmetic.

 

[vittorio]

Oh I see, I am very sorry, I should have searched better. Thank you very much for your quick response.

 

[John Mulcahy]

No need to apologise, there are a lot of settings.