PS: I did some equalizer setting that suits well the thing, we must also refined a little I pence
31 Hz ......... -> -2
62 Hz ........ -> -3
125 Hz ........ -> -3
250 Hz ......... -> -1
500 Hz ....... -> 0
1 KHz ........ -> 1
2 KHz ......... -> 2
4 ......... KHz -> 3
............. 8 KHz -> 4
16KHz ..........-> 5