All THX Certified receivers have internal test noise that THX verifies during the certification process. When using the test noise in a THX Certified receiver, the volume level is automatically adjusted to the THX Reference Level when utilizing the test noise. If you have a different receiver, it should feature an internal test noise though you may have to select an arbitrary volume level. Likewise when utilizing a test noise track on a DVD or Blu-ray.
When calibrating using the internal test noise in a THX Certified receiver, you should target 75 dB on your SPL meter. If using a test disc, it may be 75 dB or 85 dB, depending on how the tracks were mixed. The disc should provide instructions.
