A shock absorber has a pressure tube with a piston assembly slidably disposed within the pressure tube and attached to a piston rod. The pressure tube is disposed within a reserve tube and a working fluid reservoir is formed between the pressure tube and the reserve tube. The piston assembly divides the pressure tube into an upper working chamber and a lower working chamber. A base valve assembly controls a flow of working fluid between the working fluid reservoir and the lower working chamber. The base valve assembly includes a frequency dependent valve system that provides an increased level of damping for each compression stroke of the piston assembly during low frequency movements of the shock absorber. A lesser level of damping is provided for each compression stroke during high frequency movements of the shock absorber.