error message "Invalid sample rate" [SOLVED]

Mac OS X 10.9.4; Audacity version 2.0.5, but sorry I don’t know if I obtained the .dmg installer or the zip. If you can’t answer my below question without that knowledge, please advise on how I would figure this out to let you know.

Here is the main question: I have been saving my voice recordings for months by simply going to file>export>and choosing the MP3 format and hitting save. It always worked. Recently I have been experimenting with the software – trying to learn more than just the basics. Then today I attempted to save a recording in the same manner I have been doing it for months but I am met with an error message that says “Invalid Sample Rate” and “The project sample rate (44100) and bit rate (144 kbps) combination is not supported by the MP3 file format. You may resample to one of the rates below” and then it gives a default sample rate of 24000.

What I don’t know is if I inadvertently undid something in preferences to elicit this change. My preferences are set thusly: Preferences: Import/Export Make a copy of uncompressed audio files before editing (safer); When exporting tracks to an audio file: Always mix all tracks dow t Stereo or Mono channel(s) and Show Metadata Editor prior to export step; When exporting track to an Allegro (.gro) file: Represent times and durations in seconds.

Then I have the Sampling set this way: Default Sample Rate: 44100 Hz; Default Sample Format: 32-bit float; Real-time Converter: Medium Quality; Dither: none; High-quality Converter: Best Quality (slowest), Dither: Shaped.

Thank you, Linda Lutz

The MP3 export bit rate is set in the Options… button when you choose “MP3 Files” in the File Export Dialogue .

I guess you may have clicked “Options…” at some stage and knocked it on to 144 kbps, but if you require 144 kbps bit rate then you must change the sample rate to 24000 Hz (or 22050 Hz or 16000 Hz) in the “Invalid Sample Rate” dialogue. MP3 sample rate does not affect file size much (or at all if you use Constant Bit Rate) so I suggest you just choose 24000 Hz.

Here is a list of valid sample rate/bit rate combinations for MP3.

MPEG-1 layer III sample frequencies (kHz): 32 48 44.1:
bit rates (kbps): 32 40 48 56 64 80 96 112 128 160 192 224 256 320

MPEG-2 layer III sample frequencies (kHz): 16 24 22.05:
bit rates (kbps): 8 16 24 32 40 48 56 64 80 96 112 128 144 160

MPEG-2.5 layer III sample frequencies (kHz): 8 12 11.025:
bit rates (kbps): 8 16 24 32 40 48 56 64 80 96 112 128 144 160


Thank you so much Gale!