Is there a standard method to measure the effect of diffusor panels?
What kind of signal should be used (burst tone, MLS...)? Microphone omni or cardiod pattern? Distance and incident angle of the source signal and the recorded signal?
Further explanation If you read the MASTER HANDBOOK of ACOUSTIC there are a lot of diagrams showing the Time Response (Energy versus Time) of flat panels and diffusors (QRD etc..). On the diagrams you see clearly the effect of diffusion. => Direct signal => early reflections and => declining reverb part.