I no longer have the measuring microphone for the Denon X2400H, but it's only suitable for Denon devices anyway. I do have my own Yamaha microphone, though. The difference was enormous when I swapped my Yamaha RN800A for the Denon. On paper, the Denon has the same 100 watts at 8 ohms as the RN800A, and even the total harmonic distortion is almost identical, but the Yamaha can play significantly louder without distorting. It's a noticeable difference, but as I said, I didn't want to get used to it. Many people, even here in specialist shops, claim that the Yamaha YPAO isn't very good (maybe that's why they want to sell me something from them), but I've heard from many others that it's good. That's why I preferred not to use it. Should I move my speakers to another room in my large room (see picture above)? What do you think? Actually, I'd rather not. I've found a good listening position in my small room, and the ELAC RS 500 subwoofer sounds good from there. I also briefly tested it in my larger room, but couldn't find an optimal position for the bass. Is room calibration for surround sound really that beneficial? Why isn't it integrated into more expensive amplifiers? That makes me doubt it.