Quote Originally Posted by okiemax
How do you know the equalizer is needed to begin with, if not by using your ears,and how do you know you adjusted the equalizer right, if not by using yours ears? And if you listen, is it blinded or sighted listening?
The only time you really don't need an equalizer is when you have an acoustically perfect room with a flat response from 20-20000 Hz. So really, everybody needs one if you want to get technical. And I would venture to guess that a combination of room acoustics and proper equalization would make anyone completely forget about cables.

I'm no acoustic expert but I would guess that what is needed is a frequency response map of the listening room and then a plan to correct frequency fluctuations with the equalizer. Depending on the dimensions, shape and content of the room, some frequencies will likely resonate which is usually undesirable. Then you would re-measure and see if it is flat yet (flat is the goal). When you are done you can do a blind comparision between equalizer bypass and the new settings to see if you prefer them.

I would suspect you would need some fairly sophisticated equipment to map the frequency response of a room.

In the end, the difficult part is that some or most people either don't like a flat response or have never really heard a true one so it might sound odd.

These are just ramblings so take them with a grain of salt.