Convert the audio source into a digital audio file. Place the CD in the computer's CD-ROM drive and click "Rip music from CD using Windows Media Player." Use a program such as Audacity, Free Sound Recorder or Wavosaur to physically record the audio while it plays back from the device and into the computer.
To copy a vinyl record, cassette tape or other analog source, run either an RCA or 1/8 inch, 3.5 mm wire from the device's output jack and into the computer's "Line In" audio port. If using an RCA cable from the device's output jack, it requires an RCA to 1/8 inch, 3.5 mm adapter before going into the computer's "Line In" audio port.
Download and install an audio recording program such as Audacity, Wavosaur or Free Audio Recorder. Right click on the audio file, click on "Open With," then "Choose Program." Select the audio recording software and click the "OK" button.
Click and drag on the waveform to select an area to edit. Click on "Effect," then scroll down and click on "DJ EQ." Use the "Lo gain" slider to boost the bass frequencies, and use the "Hi gain" slider to boost the treble frequencies.
Click on the "Preview" button to hear a sample of the effect, then click on the "OK" button to apply the effect to the selected audio.