[Wayne A. Pflughaupt]

Does anyone know what mic comes with the Onkyo 805 and how accurate it is?

No cheap mic is accurate. As such any response-measuring device will have built-in calibration to compensate for the mic’s inadequacies, be it an expensive stand-alone RTA or a home theater receiver. REW has essentially the same thing with the calibration files used for the RS SPL meter.

That said, the Onkyo mic could be used, if you could come up with a graph of its frequency response. From that you could create a calibration file. But then you also have the issue that the mic probably has a low level signal instead of the line-level signal the RS meter’s mic element has; if that’s the case a separate pre-amp is needed, as is used with the Behringer ECM 8000 mic.

Regards,
Wayne