The use of hands-free communication in cars, computer applications and video-conferencing has created a demand for high-quality acoustic echo cancellation. In these applications have the acoustic channel typically a long impulse response in the order of 100ms. Typical lengths of adaptive FIR-filters can be 500-1500 taps. In order to reduce the complexity and also improve the convergence rate have subband processing schemes been suggested. This paper presents an implementation of a delayless subband adaptive filter. The study shows a possible suppression of about 30 dB and also a more rapid convergence than a fullband LMS-filter.