Strange REW Results

[Nick Copeland]

Hi I am new to REW. I am using the REW software to review noise levels of a machine a compressor, but that is not to critical. My when using RTA all my readings seem to have some sort of offset approx 30dB. This afternoon taking some measurements all ok - pulled the USB connection out and the offset appeared. (I had the same issue last week then it vanished I dont know what I clicked but it went away.

I have reinstalled the software, cleared the preferences, reinstalled the microphone calibration file ( miniDSP microphone).
I'm using a windows 7 laptop. I have managed to repeat this on a collegues lap top as well. I have purchased a second microphone incase it was faulty.
Any help appreciated.

Thanks N

 

[John Mulcahy]

If you remove the USB connection to the mic while REW is running it will no longer be available for as an input and the input will revert to the Windows default (which may be an internal mic, for example).

Also check that "Adjust RTA levels" is not selected in the RTA controls.

 

[Nick Copeland]

View attachment 11072 View attachment 11073 View attachment 11074 View attachment 11074 Hi some more info, and still confused. I have reviewed the check boxs - all seem to be ok. Still the same results. As I have two mics I loaded the software onto a second laptop - it shows the same results as if there is some filter giving an offset on the results. I have attached jpegs of laptop 1 & 2 (mics) next to each other also jpeg of a recording last week with results in the correct area.
Again any help appreciated.

 

[John Mulcahy]

If you open the SPL meter and click Calibrate does it say calibration is not required because you are using a USB mic with a sensitivity figure? To make sure REW has access to all the info it needs the UMIK should be selected as the Input device and the input (don't leave either of them as default).