The following thesis presents a subjective evaluation of the audio bandwidth extension algorithms available in the MaxxBass Program. The thesis explains the principle of low frequency perception and low frequency synthesis algorithms. The listening tests are conducted using a portable devices, under laboratory conditions and through the website. The recordings consist of mixed original and processed tracks. The perception of the processed recordings were evaluated. Tests are conducted on a diverse group of people. The test results indicate factors which affect the differences in the evaluation record. Moreover, this thesis presents a functional and non functional requirements which are necessary to prepare and carry out the testing process. The analyzed results indicate that original recording are evaluated better, although individual preference depends on the music genre and algorithm settings.