Can any body tell me a definite way of measuring what frequency my turntable suspension is operating at? A friend of mine is using four 'power balls' (small, very bouncy 'rubber' balls) in his suspension and tells me he believes the suspension to be operating at 3Hz. I have also experimented with these balls (3 or 4 balls and a variety of loads) but just can't see how anything like 3Hz can be achieved. I also want to experiment with magnetic isolation so any help regarding the measurement of turntable suspension frequency would be enormously appreciated.