Soundjam has a bunch of preset EQ settings, one of which is called 'bass reducer'. You can use this or you can use your own custom setting to attenuate the low frequency range. To save this EQ setting for a particular song; highlight the song in your playlist, click 'get info' and under the third tab (I'm not at home; cannot remember the tab name) save the EQ setting for the song. Now that EQ setting will be made active whenever soundjam plays the song in the future.