Matched‐field processing can be used to locate a sound source in the ocean by finding the best correlation between the signals received by a set of hydrophones and expected signals that would be received if the sound source were at a particular location. When standard (Bartlett) correlations are used, the sidelobes of a strong source may obscure the main response of a weaker source. A simple palliative for this problem is to calculate the elements of the cross‐spectral matrix associated with the strongest signal and subtract these from the observed cross‐spectral matrix. This process can be repeated for the next strongest signal, etc. This method has been suggested before for use with conventional plane‐wave beamforming [H. P. Bucker, J. Acoust. Soc. Am.62, 1222–1225 (1977)]. In this report, the sidelobe reduction is quantified as function of mismatch in the environmental parameters and the proposed subtraction method is compared to high‐resolution adaptive matched‐field algorithms.