Monitor Level Calibration with Different Room Volumes

James Hardiman

Philipp Eltz Posted the following question or comment:

Hi! I own ‘Mastering Audio’ and read in the Monitor Cal. Setup part of the book that Bob recommends 83dBSPL as an ideal listening volume as it ‘lands on the most effective point of the Fletcher Munson equal loudness curve.’

I recently read that one should set the dBSPL listening level according to room volume. My room is 42 cubic meters large and it is suggested (per some guides, SOS magazine in particular) that 76dBSPL would be better suited for that room size.

I do my best to read up and study what the brilliant minds in this field say and do, but I wondered if Bob agrees with the concept of going by room size or if one should stick with 83dBSL across the board?

Many thanks for your help!

Philipp

Hi, Phillipp

You are correct. Room Volume (which affects direct to reflected ratio), loudspeaker distance, high frequency response and transient response all affect the perceived loudness of the signal from the loudspeakers.  The SMPTE has a table of offsets according to room volume. However, depending on the acoustics of the room and the amount of absorption, there can be variants. it’s basically related to the direct versus reflected ratio, since transients are increased and perceived loudness is greater with a higher direct to reflected ratio. That is related to room volume, but still the SMPTE table is an approximation and also reflects the acoustics of large theaters, which are usually very dry and far less reflective than homes and small studios. 

So, the closer the speakers are to you, the dryer the room, the brighter the speakers, the more direct their polar characteristic, the lower you will have to calibrate your 0 dB point. This is a generalization. 83 dB calibration point for the 0 dB monitor level works for me with my loudspeakers in my fairly large room, placed at about 9 feet from the listener. Your mileage may vary. So how do you arrive at a correct reference?  Fortissimo should feel very loud. Mezzo forte should feel comfortable and natural and at approximately the natural level of the acoustic instruments being reproduced. Do this with a wide dynamic range recording with 18 dB or greater of peak to loudness ratio and you’ll arrive at a 0 dB point that should work. 

Then you offset the monitor gain downward according to the K-System.

In Studio B my monitors are closer and the room is smaller and dryer. I listen to a particular wide dynamic range recording about 3 to 5 dB lower than I do in Studio A. But I soon learn what Studio B does and can work with it well. 

Best wishes,

Bob