Small and flat loudspeakers usually result in poor low-frequency (or bass) responses. Conventional gain equalization does not help significantly and may even result in overdriving and distortion. A psychoacoustic approach has been found to be suitable in tricking the human ear to perceive the fundamental frequency from its higher harmonics. Past research efforts have generally focused on weighting the harmonics based on the loudness matching method, but no work on timbre matching has been carried out so far. In this paper, we propose a new timbre matching technique, which can improve the sound quality of the psychoacoustically enhanced bass. This approach adjusts the amplitude of harmonics to produce similar timbre as the original audio content. Objective and subjective tests are carried out to compare the audio quality of the psychoacoustic bass enhanced signal using the equal-loudness weighting and the timbre matching methods.