I'll be needing to calibrate my monitor sound levels when my new RME FireFace UCX Audio Interface comes in this Thursday. I'm having a friendly discussion with my Sales Engineer at Sweetwater about how I've calibrated my system in the past.

I use a pink noise sound track in Sonar with a calibrated output level, and set up my interface and monitor gain levels to give me 78dBC on my sound level meter. I've read several articles in the past on how to do this and they all recommend 78dB for smaller rooms like mine and specify C weighting vs. A.
I master with Izotope Insight plug-in at the end of the chains and with a comfortable listening level try to have the output average at -16dB sound units. (I not trying to win a loudness war)

My Sweetwater man says that I should use A-weighting and 85 dB SPL.

I looked a 12 dozen different WEB sites on this topic today and they all suggest C weighting and 85 dB for a large studio and 75-78 dB for a smaller room.

Any comments?

Walt

Bob Katz recommends C-weighting. A-weighting is designed for measuring industrial noise levels, not reference monitors.
 
But if you use band-limited pink noise as Bob recommends (rolling off below 500Hz so you're essentially ignoring low frequencies when measuring), then your SPL meter will read the same with either A- or C-weighting, since both curves are the same above 500 Hz.
 
If 78 dB has worked well for you so far, stick with that. 77 dB is what I use, chosen not by any scientific criteria but just because it's a comfortable level I can listen to for a long time without fatigue, and comparable to the level I like to listen to music at normally.
 
I strongly believe that mixing at a consistent level is far more important than any specific loudness. Your brain will adapt to whatever level you choose, as long as it's comparing apples to apples day-to-day.