My 2c.Rounded off in a way that it lacks transients and lacks inner detail. Think if you put a slight, but significant downward slope in EQ and added a little low level barely perceptible noise to cover up the lower level details. Done right, you won't think it rolled off or noisy, but it sounds slow and unresolving.
In the old days the difference in a Shure MM cartridge and a good MC cartridge.
Many audiophiles perceive the speed incorrectly, many issues in the room, like enhancements in the sub bass region can destroy the image of transients and can mask the details
If there is some huge enhancement in a random frequency you are going to hear a lot of that distractive thing in that specific frequency, BUT NO AUDIOPHILE after a listening sesion are going to tell you something like '' hmm, i find a bump at 66hz, and my golden ears says it's around +3dB, also there is a cancelation around of -2dB at 100hz ''.
You are going to need a microphone.
No one after a listening sesion are going to tell you how much nulls and enhancements in a room you have, in fact going to listening in a store a speaker and judge the woofer is the most worthless thing.