Sean,

The correct procedure is to set your volume to any level to begin with, turn on the test tone, rotate the volume to the 0db position, refer to my last post, for details about correct positioning for you and the meter. Adjust individual levels to get to 75 or 85db as you so desire. If you say that 85 does not sound good with your setup then use 75. make sure that you hold the meter correctly and sweep it from side to side and adjust for an average reading.

Hope this helps you.

John