I use the Rives audio test CD
http://www.amusicdirect.com/products/detail.asp?sku=ARIVESCD2
Great test cd, calibrated to use with the Radio Shack SPL meter.
http://www.amusicdirect.com/products/detail.asp?sku=ARIVESCD2
Great test cd, calibrated to use with the Radio Shack SPL meter.