Manual

If one looks at the RIAA eq curves; the blue graph is the eq for the disk cutter and the red graph
is the record play back equalization. Part of the reason for the lack of high frequency head-
room in vinyl records has do to the large HF boost on the cutter side and it’s mating HF reduc-
tion on play back. The 2 eq curves result in flat frequency response. At 10 KHz the boost with
respect to 1 KHz is 13.7db and around 27 db with respect to 100Hz. The resulting distortions
and HF compression are part of what creates the sound. There are additional mechanisms
that affect the HF headroom, limitations in what the cutter can physically do and what the play
back stylus can do are examples. The graphs help explain in a simple manor the change in
HF headroom. In music, a full amplitude 10 KHz signal does not happen so the system works
as it has for tens of years.