Recording
You should record audio at the best quality you can manage, using a lossless file format (like .wav). However, the files will have to be processed for sharing to be lighter.
Sharing
When it comes to sharing your audio as a podcast, MP3 and M4A files are the only audio filetypes that are supported for podcast apps (like Apple Podcasts). Acast supports both file formats.
We recommend uploading mp3 files with a bitrate of 128kbps. These typically have the right balance of good audio quality and small size, which your listeners and apps will appreciate.
Acast will encode your uploaded files at 128kbps, which will not impair the perceived quality for your listeners.
If you have recorded in a different file format (like .wma) use your audio editing software (such as Garageband or Audacity) to export the episode audio file as MP3 or M4A as recommended above.
What are the limits?
Most people use the Apple Podcasts app to listen to podcasts. Apple has set the file limit to 150MB for all files downloaded over a cellular connection (including apps, ebooks, and videos).
When your listeners try to play your episode, they are greeted with a pretty unhelpful message—"episode unavailable"—which is a frustrating experience to say the lease. To help our podcasters avoid this issue, Acast sets the internal limit to 150MB also.
To make your file smaller, use your audio editing software (like Garageband or Audacity) to export the episode audio file at a lower bitrate. Choose to export at 128kbps MP3.
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I am an avid enthusiast and expert in the realm of podcasting, possessing a wealth of knowledge and hands-on experience in the intricacies of recording, editing, and delivering podcast content. Allow me to demonstrate my expertise by delving into the concepts mentioned in the article, providing insights and additional information to enrich your understanding.
Recording Quality and File Format: Recording audio at the highest quality is paramount for a compelling podcast. Opting for a lossless file format, such as .wav, ensures that the initial recording captures the nuances of sound with minimal compression artifacts. This is crucial for maintaining audio fidelity throughout the production process.
Sharing and Compatible File Formats: When it comes to sharing your podcast, compatibility is key. Podcast apps, including the widely used Apple Podcasts, support specific audio filetypes. MP3 and M4A are the recommended file formats for podcast distribution. Acast, as a platform, facilitates both these formats, ensuring seamless compatibility with various podcast apps.
Bitrate Considerations: The article rightly emphasizes the importance of choosing an appropriate bitrate for your MP3 files. A bitrate of 128kbps strikes a balance between maintaining good audio quality and keeping file sizes manageable. This is crucial for ensuring that your audience experiences high-quality audio without compromising on download times and storage requirements.
File Size Limits and Optimization: Understanding the limitations imposed by podcast platforms, particularly Apple Podcasts, is essential. With a file limit of 150MB for cellular downloads, exceeding this limit can lead to a frustrating user experience with error messages like "episode unavailable." Acast wisely aligns its internal limit with this threshold to prevent such issues. To stay within these limits, podcasters are advised to optimize their audio files by exporting them at lower bitrates, such as 128kbps MP3, using audio editing software like Garageband or Audacity.
Podcast Editing Software: The article mentions using audio editing software, such as Garageband or Audacity, to handle various tasks like format conversion and bitrate adjustment. These Digital Audio Workstations (DAWs) are instrumental in refining podcast content, offering a range of tools for editing, enhancing, and exporting audio files according to the desired specifications.
Additional Resources: The article concludes by pointing to related articles and FAQs, such as optimizing audio files for podcast delivery, Acast FAQs, and guidance on recording and editing podcasts. These resources serve as valuable references for podcasters seeking to enhance their skills and troubleshoot common issues.
In summary, successful podcasting requires a nuanced understanding of recording technologies, file formats, bitrate considerations, and platform-specific requirements. Armed with this knowledge, podcasters can deliver a seamless and enjoyable listening experience to their audience.
