Pat, the auto-calibration system on your 705 is excellent and gives results that should be at least as accurate with respect to calibrating sound levels as you could accomplish by setting the levels manually(taking into account the added factor of human error)with the aid of the SPL meter. Rather unrealistic comments are sometimes read concerning checking the auto-set levels with an SPL meter to see how far the auto setting was "off", when in fact it's the user who's off.
The digital RS meter(which I also use)is very useful for things such as checking average and maximum sound levels when playing various sound sources, but isn't essential for the calibration process if the receiver can do the job.
