For the 846 it's like taking an EQ and dropping everything from 400Hz to 14KHz centred around 3KHz down in a smooth U shape if that makes sense. How many dB depends on how high the output. The result is only bad if you don't like that. With a high enough output the 846 would start to sound like a Westone and their typical upper mid scoop out. Plenty of people like those so it isn't about good and bad but preference. For me... that's death. For others... heaven.