# Calibration Files



## alegon (Jun 25, 2009)

Hello Bruce,

First post here...great program by the way!

I have everything working properly I believe. I am using a basic laptop (Vista), my trusted old analog RS SPL meter, ECM8000, and a Tascam US-144 (great clean unit) mixer. I went by the book on the initial four steps calibration (I/O-sound card-levels-SPL reading). I have made a few measurements and they appear to be OK...mainly room responses off axis. 

My main questions...do you must have the calibration files loaded prior to making a measurement..1) ECM8000-CS for wide bandwidth testing and..2) RS-33-2050-CS to calibrate proper SPL readout first?

I am enjoying the software a lot!

Thanks,
Alex


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## brucek (Apr 11, 2006)

> My main questions...do you must have the calibration files loaded prior to making a measurement..1) ECM8000-CS for wide bandwidth testing and..2) RS-33-2050-CS to calibrate proper SPL readout first?


When you are using a microphone with REW, you never actually connect the SPL meter. It is only used to get a rough 75dB reading at the listening position (near the ECM8000). 

During the Check Levels routine, when you are adjusting your receiver to obtain 75dB at the listening position, you hold the SPL meter near the ECM8000 and set the level with the receiver to 75dBSPL. Then you put the SPL meter away - it was never connected and no cal file is needed.

Now you know the level is approximately 75dB. You now set the input level to the soundcard (the ECM8000 is connected, and its cal file is already loaded).

Anyway, on a side note. No, you don't require the mic cal file loaded when you measure (although, why wouldn't you have it loaded). The cal file can be loaded later and applied to the previous measurement by using the IR Windows pop-up and the Apply button.

brucek


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## alegon (Jun 25, 2009)

Got it...I will play more this weekend. I noticed you can loaded after a measurement.

Thanks,
Alex


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