Ajax i just found the article off the thread. Here they say to check volume by A setting (that's where my confusionwiththe dial and the zero came in) If I use what you said c and slow and then use A and slow The C reading is substantially Louder....What to do?? Not sure i understand the difference in A and C weighting I guess it's in the range of sound (Higher tones?) Thanks for any clarification...Here's the link
http://audiophilia.com/hardware/spl.htm
From The article:
While simulating the volume level of a large rock band or full symphony orchestra in your listening room can be a lot of fun, remember to keep an eye on those SPL's to ensure that they are within safe levels. The following table from the U.S. Department of Labor (also included in the excellent documentation accompanying the Radio Shack sound pressure level meter) gives data on permissible sound level exposure.
To use the Radio Shack sound pressure level meter to ensure that you're listening to your system at a safe level, first set the meter's weighting and response switches to the 'A' and 'SLOW' positions respectively. Play some music on your system at your normal listening level (no cheating now!) and adjust the setting on the meter's rotary dial such that the average reading is around 0dB. Note that a setting which is too low will tend to "peg" the needle to the right, possibly damaging the meter. Given an average reading of 0dB, your measured listening level is given by the setting of the meter's dial. For example, if the meter has an average reading of about 0dB and the dial is set to about 90dB, then your listening level is about 90dB. According to the table above, you can safely listen at this level for about eight hours per day, although I would use this table merely as a guide and let common sense prevail. Making a habit of using the sound pressure level meter to measure the average sound level of your system at each listening session is a simple way to ensure that no harm will come to your hearing through regular use of your audio system.
