Abstract: A Method for filter tuning using direct digital sub-sampling is provided. The tuning is accomplished in the digital domain by determining the filter characteristics from the shape of the transfer function. The input signal (1) is passed through the filter (3) and is then sub-sampled by and Analog-to-digital Converter (ADC) (5). The sub-sampled signal (6) is then processed in the digital domain using a digital circuit (7) that is used to determine the center frequency (Fc) and Quality factor (Q) and/or other important filter parameters. The Fc, Q and/or other important filter parameters are then adjusted by generating digital control signals (8) that can be converted to analog signals (10) using Digital-to-analog Converters (DACs) (9).