[brucek]

My question is: is this file calibrated from horizontal or vertical

All the calibration files on our download site are the frontal incident (horizontal position).

For listening position measurements we recommend that the meter or mic be oriented vertically with a forward angle of about 10 - 20 degrees to capture a good mix of direct and reflected sound for "room" measurements. For near field measurements we recommend a horizontal position.

brucek

 

[brucek]

so for measuring in a vertical position (with 15 degrees) a *.cal file from vertical calibration would be more exact??

Well, the vertical calibration means the mic should be oriented vertical. The reason we recommend tilting the mic 10-20 degrees toward the front of the room, is that the generic cal file is horizontal. For listening position (where only the mains are playing in REW), a vertical orientation tilted toward the source (rather than horizontal) will give a nice blend of the mains source plus reflections.

But, if you have a vertical cal file, use it that way. The vertical and horizontal files are close enough, that we weren't about to provide them both as a generic set since the errors in using a generic file overwhelm any small differences in those two files. If anyone is really concerned about accuracy in a home setting (where a mic movement of a few inches can realize several dB change) then they should get their mic calibrated.

brucek