Step 1: First of all import the audio file that you wish to work with.

Step 2: Now select the portion of the audio that you want to work with within the file.  Do this by using the selection tool.  Click at the beginning of the part you wish to work with then drag to the end point that you want.

Step 3: Then go the drop down menu labeled “Effects” and select Bass and Treble.

Step 4:  A pop-up box will show up.  Type in the amount of Bass you want to add to the selection that you picked by adjusting the dB amount of Bass using the slider or typing in the amount.  You can preview the change by clicking preview.  Then click okay when you are happy with the change.

Step 5:  After you click “OK” the change will take place.  You can undo the change by pressing “Ctrl+Z” or by clicking the “Edit” drop down menu and selecting “Undo Bass and Treble”.  Congratulations you’ve adjusted the Bass!  You should see the change in the selections waveform.