Originally Posted by manbear
Originally Posted by adupree
Adding EQ across an output causes a false representation of the actual sound. You do not want a flat response, we do not hear flat. Look at equal loudness contours. Also most EQ adds phase distortion.
Call it "flat," "equal loudness contours" (which means audibly flat anyway), whatever -- the point is that every headphone has a unique frequency response curve that differs from the ideal response. If I listen to the same track on different headphones with no EQ, I will hear a different frequency response on each. Neither is likely to be an accurate representation of what the mixing engineer heard. EQ can correct these differences, bringing the headphone's frequency response closer to the equal loudness contour.
Your criticism of EQ only makes sense if the mix is designed exclusively for people using the exact same headphones as the mixing engineer. A headphone different from what the mixing engineer used will not reproduce the "actual" sound the mixing engineer intended unless you use EQ appropriately. Likewise, unless the mixing engineer's headphone's frequency response matches the equal loudness contour, he/she can use EQ to correct the difference.
You are right about phase shifts though.
I disagree that equal loudness contours means flat. They show the way we hear frequency loudness vs overall loudness. Yes headphones and speakers alike have different frequency responses, but if you look at the headphones and speakers which are referred to as some of the best options for mixing/mastering they all have similar responses which are very similar to equal loudness contours. Therefore, by changing this with EQ it effects the actual sound of the mix. This is why you do not see most studios, whether mixing or mastering, place EQ across their speaker systems. The way they fix problematic frequencies are with acoustic design and treatments. I understand this can't be done with headphones, but you also are not dealing with a room which will affect the response. Yes each person's ear-canal will modify the actual sound of the headphones, but very slightly.
If a mix is done properly, it will translate very well to any playback system and will give an accurate representation of what the mix engineer heard. The OP is using K701s which are great headphones for using as a ref for mixing/mastering and running an EQ on them can hinder his results.
OP I strongly advise not to place an EQ on the headphones. Just get a good amp/DAC.