Hi,
Here is the response curve of my system, from the listening position, after equalization :
View attachment 13279
It is divided into three parts :
-The part above 5 kHz is not relevant. It was measured with both speakers playing at the same time, and thus the graph is very inaccurate because of possible interference between the two tweeters.
-The part between 200 and 5000 Hz follows the natural response of the speakers. Only isolated peaks or dips have been corrected, and the positive and negative corrections have been balanced.
-The part below 200 Hz is my own personal preference. I tried many things during one year, and nothing else than this could satisfy me.
The speakers are Neumann KH-120 near-field monitors. The listening distance is 2 meters, in a 3.4 x 6.2 x 2.5 meters room with no acoustic correction. They are not looking right at the listening position. They are nearly parallel. The reverberaton time at the listening position is 0.45 seconds.
The DSP correction is active from 35 to 900 Hz and performed by a MiniDSP 2x4 :
View attachment 13282
Hi Cosmik. Paul Hales gives a plausible explanation in this long video
It can be summarized this way :
-The house curve is the result of the direct field and the diffuse field
-Speakers are directional : the direct field has more high frequencies than the diffuse field
-Natural sound sources, such as voice, or music instruments are directive too
-We listen to music with nearly no diffuse field recorded
=> When the speakers are perfect in anechoic conditions, because of their directivity, the house curve they give when they are not equalized mimics the sound that the real instrument would give in the same room.
...if this is right, it would mean that small speakers would be better at reproducing small instruments because of their wider directivity, and large speakers would be better for big instruments because of their narrower directivity.