Two sampling frequencies used in digital audio are 48000Hz and 44100Hz. While the human ear can barely detect the difference between the two, computers and other devices are a little bit more discerning. Some programs and players will read only MP3s encoded with a 44100Hz sampling rate, which is a problem if your MP3s are encoded at the higher 48000Hz rate. Thankfully, there are many different audio conversion programs that can take a file encoded at the higher frequency and create a new copy at the lower frequency.
Using Format Factory
Download and install Format Factory (see Resources). Launch the program after installation is complete.
Click on "All to MP3," and drag the MP3 file you want to convert into the program window.
Go to "Output Setting." Click on the small arrow next to "Sample Rate (HZ)," and choose "44100" from the drop-down menu. Click "OK" to save the changes.
Click "Start" to convert the 48000 Hz file to a 44100 Hz file. After the conversion process is complete, click on "Output Folder" to open the folder where the file was saved.
Using Free MP3 WMA Converter
Download and install the Free MP3 WMA Converter (see Resources). Launch the program after installation is complete.
Drag the file you want to convert into the "Files to Convert" section of the program window.
Click on the drop-down menu next to "Output Format," and select "MP3."
Click on the button next to "Format Parameters," and click on the "General" tab. Under "Sample Frequency," select "44100 Hz" and then click "OK."
Click "Convert!" and the file will be converted to 44100 Hz.
Download and install Super (see Resources). Launch the program after installation is complete.
Right-click anywhere in the program window, and select "Add Multimedia Files" from the menu that appears. Choose the file you want to convert, and click "OK."
Click on the drop-down menu under "Select the Output Container," and choose "MP3 (Audio Only)."
Go to the "Audio" section. Under "Sampling Freq," choose "44100."
Right-click on the program window again, and select "Output File Saving Management." Choose the folder in which you want to save the new file, and then select "SAVE Changes."
Click "Encode (Active Files)" to convert the file to the new sampling frequency.