Yeah, but that's probably because your centre channel is relatively smaller than on the cinema audio systems the 5.1 track was designed for. So setting it to +7

Yeah, but that's probably because your centre channel is relatively smaller than on the cinema audio systems the 5.1 track was designed for. So setting it to +7dB at home is probably normal/expected. After all, (Tenet aside) we don't experience these problems at actual cinemas, where the centre channel is a huge speaker stack behind the screen, and the surrounds are relatively small by comparison. But I agree that it's a common issue on on home setups.