I also found this and used google translate. Is the frequency response and/or axel deviation comment related to phase angles? Not sure if the wording is different because of the translation.
"Also by measurement the relationship between S-1EX and S3-EX is unmistakable. The frequency response looks almost like drawn with a ruler and extends down to about 40 Hertz. From five kHz is a slight ripple into play when the axial deviation of 30 degrees (dashed line), however, is negligible. Straightened out into the room, the Pioneer actually sounds a bit faster and more coherent dunk. The impedance is danzverlauf critical, and the jump response is in order, with the enormous time accuracy of their sister, it can not record the S-3 EX bass but because of the delay."
Thanks