Before running Audyssey XT setup, I turned Audyssey off, set the Marantz SR6006 to 0 db offset, and adjusted the channel level of each speaker (inc subwoofer) to 75 db at the central listening position. I’ve read this is important to get consistent results. I ran Audyssey, and the four surround/height speakers were chirping at about 45-47 db at the central listening position, the front L/R and subwoofer about 52-57 db, much lower than the 75 db I had calibrated them to. At the second listening position, something strange happened. As the front L speaker had just finished its series of chirps (or pings, whatever you call them), I made a loud “creek” by stepping on my wooden stairs. The mic picked up that noise, and the front L speaker re-performed its chirps at a much louder volume, approx 65 db at the main listening position. The chirp volume of all other speakers remained the same. The image attached shows the end filter result of the front L/R speakers. You can see the L speaker curve is very similar to the R speaker curve, but larger offsets are applied to the L curve, particularly in the high frequency roll off. (Other times I have ran Audyssey the L/R curves are nearly identical, so this isn’t a room acoustics issue). Question: It’s obvious that the chirp volume level plays an important role in the resulting curve. Why did my 75 db calibration have no effect on chirp volume level? Question: What happened at the second listening position that caused the L speaker to re-perform its chirps at a higher volume? Question: What level is the chirp supposed to be??