Need some guidance please

[ebenai]

Hi guys: I'm familiarizing myself with REW, have made a ton of measurements but there a few things that don't have clear:
1) In the check level procedure it is recommended that the SPL meter range be set to 80. I'm using the RS digital meter. If I set the range at 80, I cannot get up to the -18 db recommended level. It will go up to around -24 or so. If I set it up at 70 it works perfect. IS this OK will the measurements still be valid.

2) I calibrated the SPL meter and in addition loaded up the calibration file which I believe is to try correcting some of the inaccuracies of the meter. The problem is that I don't see any differences in the measurements with or w/o the calibration file? What Am I missing here?

3) I'm still in the diagnostic mood here. Should I be using the set target levels menu and filter task? I think these are used when one is ready to begin correcting abnormalities?

I would appreciate any help

Thanks

[brucek]

If I set it up at 70 it works perfect. IS this OK will the measurements still be valid.

If you have the range set to 70 and you set the meter reading to 75dBSPL during the Check Levels routine, then you don't have much headroom left when you run your sweep in the event you have some peaks in the response. So, you will have to check (directly after) after a measurement that the meter didn't clip by examining the SCOPE tab in REW and look at the input signal for distortion. Otherwise the results will be fine.

I calibrated the SPL meter and in addition loaded up the calibration file which I believe is to try correcting some of the inaccuracies of the meter. The problem is that I don't see any differences in the measurements with or w/o the calibration file? What Am I missing here?

You're missing the fact that if you remove the cal file, the change has to be enabled by clicking on IR Windows icon and select Apply Windows (while watching the graph change).

Should I be using the set target levels menu and filter task? I think these are used when one is ready to begin correcting abnormalities?

Those are used when you want REW to recommend filter settings for an equalizer.

brucek