What are Correction Values and how are they used?
For years most enthusiast have used the Radio Shack SPL Meter as one of the tools for measuring their sub response. The big drawback with using this RS Meter is the mic in the RS Meter is not accurate. Traditionally we have used what is known as the RS Correction Values to offset the inaccuracy of the RS Meter. By adding these values to the corresponding frequency, it causes the RS Meter to be more accurate. Below is the traditional RS Correction Values (although we now recommend not using them - keep reading):
Although these values have been generally accepted, they are not accurate. How do we know this? Well on more than one occasion there have been individuals, including myself, who have measured the RS Meter mic with these correction values against a professional calibrated mic with a flat response. For on my latest test of the newer analog and latest digital meters... see
this thread. Bottom line... the gool ole traditional RS Correction Values are NOT accurate. If you use them then you will most likely be seeing an inaccurate response from your sub... especially in the extreme lower frequencies.
So... having explained this, we now have a new set of RS Correction Values and instead of them being 1/6 octave, they are 1/60 octave from 10hz to 200hz, which is the typical range measured for sub response. There are new *.cal files with these correction values for the older analog meter, the newer analog meter and the latest digital meter. You can download the new *.cal files by logging in and going to the
Downloads Page. These are the *.cal files for use with Room EQ Wizard. If you need to know how to load them into REW, see the first post in
this thread.