setting of the gain of the controller 4 as described previously the quotient a c is found by setting the frequency u03c9 2 of a sine wave generated by the signal generating means 9 so as to be equal to f c if the quotient a c produced by an arithmetic and logical operation is equal to unity the system gain at the frequency f c becomes equal to 0 db so that there is no necessity of adjusting the gain of the controller 4 if the quotient a c is not equal to unity gain adjustment is made by multiplying a controller gain coefficient k by c a so that the system gain for the frequency f c is equal to 0 db referring to fig1 a second embodiment of the method of automatically setting the frequency characteristics of a vcm as position controlling means of the disc recording reproducing apparatus of the present invention is now explained a target position signal indicating a pre set track position is summed by an additive node 2 with eccentricity data from eccentricity data storage means 1 and the resulting sum is supplied to an additive node 3 the additive node 3 then takes the difference of the signal from the additive node 2 and the position detection signal as detected by a position detection unit 8 to produce a synthesized signal a which will fix the recording reproducing head 6 the signal a is provided to the controller 4 which then outputs a signal for controlling the position controlling means for the recording reproducing head 6 that is the vcm 5 an output of the controller 4 is supplied to.