Audio preservation · Format guidance · Digital access
Choose the right digital format for your audio archive. Understand preservation masters, lossless files and convenient listening copies for recordings digitised by Oxford Duplication Centre.
The best format depends on how a recording will be preserved, edited, shared or heard. An archive may need a high-quality preservation master alongside smaller access copies for researchers, staff or family members. Planning these outputs at the start helps maintain consistency across a collection.
For magnetic tape, cassettes, DAT, ADAT, open-reel audio, 78rpm records and other sound carriers, we can help you specify suitable digital deliverables for the intended use.
These are the main formats clients commonly consider when planning audio digitisation.
WAV is widely supported for uncompressed PCM audio. Broadcast Wave Format (BWF) builds on WAV and can carry embedded metadata, making it particularly useful for professional and archival workflows.
Suitable for high-quality preservation masters, editing and long-term collection management when accompanied by appropriate storage, documentation and checks.
AIFF is an established uncompressed audio format associated historically with Apple systems. It can carry high-resolution PCM audio and is suitable for production and preservation workflows where specified.
WAV/BWF is often the more common default for institutional exchange, but the right choice depends on client requirements and the destination workflow.
MP3 uses lossy compression to reduce file size, making it practical for everyday listening, email delivery and web access.
It is generally best treated as a convenient access copy rather than the sole preservation file, because some audio information is discarded during encoding.
FLAC reduces file size without discarding the encoded audio information. It can be useful when storage efficiency and lossless playback are both important.
Check that the intended archive, playback software and delivery system support FLAC before choosing it as a principal deliverable.
Audio CD uses 16-bit, 44.1 kHz PCM audio. It remains useful where physical disc playback is required, but it is not a substitute for a higher-resolution archival master when one is specified.
CD creation may also involve track divisions and disc-authoring requirements.
AAC and other delivery formats can provide practical listening files for specific devices, platforms or streaming systems.
Choose these for a defined access purpose and retain a suitable preservation master separately when long-term preservation is important.
Bit depth affects the digital representation of the recording’s dynamic range and low-level detail. A higher bit depth provides more precision when capturing the signal.
16-bit is associated with CD audio; 24-bit is commonly specified for professional digitisation and preservation workflows.
Sample rate describes how many audio measurements are captured per second. Common choices include 44.1 kHz, 48 kHz, 96 kHz and 192 kHz.
The appropriate rate depends on the source, the project specification and the intended preservation or production use.
Uncompressed PCM WAV/BWF or AIFF retains the captured PCM data without lossy encoding. Lossless compression such as FLAC reduces file size without throwing away encoded audio information.
Lossy formats such as MP3 create smaller files by discarding information and are normally most useful for access copies.
| Purpose | Common choice | Why it may be suitable | Considerations |
|---|---|---|---|
| Archival preservation master | WAV or BWF, often 24-bit / 96 kHz where specified | Uncompressed PCM, broad support and potential for embedded metadata with BWF. | Agree the exact specification before digitisation; file integrity and managed storage matter as well as format. |
| Editing and production | WAV or AIFF, commonly 24-bit at the project’s required sample rate | Suitable for professional editing and production workflows. | Match the receiving studio, software or production specification. |
| Research and general listening | MP3 or AAC access copy | Smaller files are easier to share and play on everyday devices. | Keep a separate preservation master; lossy compression removes audio information. |
| Lossless access with smaller files | FLAC | Reduces storage needs without lossy audio compression. | Confirm compatibility with the archive and access systems. |
| Physical disc playback | Audio CD, 16-bit / 44.1 kHz PCM | Useful when a conventional audio disc is specifically required. | Not usually the only deliverable for a preservation-focused project. |
Oxford Duplication Centre digitises a broad range of audio carriers, from personal recordings to complex professional and heritage collections. Output options can be agreed to suit the source material and your project specification.
High-quality PCM files for archival storage, research, production and future use, with metadata options where required.
Uncompressed files for workflows that specify AIFF or need compatibility with particular production environments.
Convenient listening copies for distribution, internal review, family access or online use.
Audio CD output where a physical disc is requested, subject to the source and project requirements.
Professional capture options can include 24-bit / 96 kHz and, where appropriate and agreed, 24-bit / 192 kHz output.
Discuss consistent file naming, folder structures, metadata, quality assurance and separate master/access files for large collections.
Research, broadcast, editing, public access and personal listening may require different deliverables.
For valuable or unique recordings, consider retaining a high-quality master and creating smaller access copies from it.
Institutions may have mandatory bit depth, sample rate, metadata, naming, checksum or delivery requirements. Share these before work begins.
Tell us what media you have, the size of the collection and how the digital files will be used. We can help you plan appropriate formats and delivery options before the project starts.
