# How to calibrate MP-1r-KIT SPL with REW?



## SirLordComic (Mar 15, 2013)

I have the MP-1r-KIT Acoustical measurement kit, and I have a dumb question.

What is the best way to calibrate the SPL with REW?

I have read the MPR1 manaul which states to place the mic 10" or so from driver, and find 94db LED to light up with 1kHz tone. Then adjust gain until -10dbv lights up.

My question is: do I leave it 10" from the driver and then do the REW SPL "alignment", or do I need to get the mic out in the room where I will be making my critical measurements for the listening position.

Sorry, I have very rudimentary understanding of all this.

Thanks for the post on the subwoofer testing; I will use it once my sub-amp is repaired shortly.


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## JohnM (Apr 11, 2006)

To do the SPL calibration on REW you can leave the mic in place, with the 94dB and -10dBV LEDs lit on the MP1r preamp; click the Calibrate button on the REW SPL meter, then enter 94dB as the SPL figure and click OK. 

A couple of things to take care with before doing the REW SPL calibration:

- adjust the level of your tone, or the distance of the mic from the driver, to the point where the 94 dB LED just reaches full brightness
- adjust the input level on the soundcard you have the output of the MP1r plugged into to get the level on the horizontal bar on REW's SPL meter reading somewhere around -12 to -18 dB FS

If you change the MP1r gain or the soundcard input level you will need to redo the REW SPL calibration.


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