Download Audacity. Audacity is a free music editing program that you need to convert your music from stereo to mono. Once you download Audacity, install it on your hard disk.
Run Audacity and import the music you want to convert. To do this, click on ‘File’ and select ‘Open.’ Then select the file you want to convert to mono. Make sure the file you are converting is already in stereo.
Look at the box that appears after you import the file. You should see blue waveforms. To the left of the waveforms you will see a lot of numbers and other settings in a box. In the upper left corner of the box, locate the arrow (located to the left of the 1.0).
Click the arrow and select ‘Split Stereo Track’ from the drop-down menu. You will now notice that the track is divided into left and right channels that you can control.
Click on the arrow at the top (left channel) waveform select to the left of the top waveform’s 1.0 mark.) Select ‘mono’ in the drop-down menu.
Click on the lower arrow (Right channel). This will be to the left of the 1.0 waveform of the lower waveform. Select ‘mono’ in the drop-down menu. At this time, the boxes to the left of the upper and lower waveforms should both say ‘mono’. If you still say ‘right’ or ‘left’, make sure you followed the steps above and switched each channel to mono in the drop-down menu.
Now export mono song by clicking on the File tab and selecting one of the export options. Select the directory you want to export the file to and you are done.
Tips and warnings
Although we often think of stereo recordings as a technical step forward over the mono format, some manufacturers have historically preferred mono over stereo. Especially in the early days of stereo, many manufacturers saw stereo as a bit of a gimmick and mostly spent time making the monomix perfect.
Listen to Brian Wilson’s production work on The Beach Boys’ PET SOUNDS in both mono and stereo and you will probably hear the more powerful effect of the mono recording over the stereo recording. Also, if you know you will be listening to music on just one headphone, it’s fun to have all the instruments mixed in a single speaker. Learn how to take your stereo MP3 files and convert them to mono format.