Audio Encoding
Spoken Word Shows:
Stereo Bit Rate - 192 kbps or lower (In Mono this gets cut in half)
Sample Rate - 44.1 kHz
Channels - Mono
Music Shows:
Stereo Bit Rate - 128 kbps or lower
Sample Rate - 44.1 kHz
Channels - Stereo
Stereo Mode - Joint Stereo
Your bit rate can be set as low as 96kbps (some even go as low as 64kbps). As noted above, if using mono, many editors will automatically cut the bit rate in half. If yours does not, you can simply set your rate at 96kbps.
Your editing software may offer a checkbox for VBR or Variable Bit Rate. Do not check this box, your bit rate needs to be constant. The reason behind this is variable bit rate will change how different players and systems scan the file, and they often will either be incompatible with VBR completely, or at the very least will get the duration of the file incorrect causing the file to end up cut off towards the end.
Libsyn recommends utilizing MP3 files, however; M4A files are supported by Libsyn as well. Not all podcast directories support M4A, but they all support MP3. For greatest compatibility, upload MP3 files for episodes distributing to podcast directories.
These settings will give you the best bang for your buck with relation to audio quality and media file size.
Have additional questions? Reach out to our friendly support team at support@libsyn.com.