Sampling rate
How Often the Signal Is Measured
Sampling rate is expressed in kHz. Different projects may use 44.1 kHz, 48 kHz, 96 kHz or higher rates depending on the source and intended use.
Knowledge Centre · Audio Preservation
Audio Preservation & Digitisation
Understanding how ageing audio recordings are assessed, digitised, quality controlled and preserved as high-quality digital files for future access.
Preserving Sound Before the Original Becomes Unplayable
Magnetic audio recordings can contain irreplaceable music, interviews, oral histories, broadcasts, research material and family memories. Preservation begins by understanding the original medium, its condition and the recording itself.
This guide brings together our key Knowledge Centre articles covering analogue audio digitisation, sampling rate, bit depth, channel configuration, WAV and BWF, tape deterioration, tape baking, digital preservation and quality control.
Assess the original
Identify the format, condition and recording configuration before playback.
Capture carefully
Use appropriate professional playback and analogue-to-digital conversion.
Verify the files
Check channels, levels, sampling rate, bit depth and file integrity.
Preserve for access
Maintain high-quality masters with suitable access derivatives.
01 · The starting point
What Is Analogue Audio Digitisation?
Analogue audio digitisation converts the continuous electrical signal from an original recording into digital data. The quality of the result depends on the source, playback system, signal path and capture specification.
Good preservation practice aims to capture the recording faithfully rather than simply making a convenient listening copy.
- Original tape carefully assessed
- Appropriate playback equipment selected
- Analogue signal captured through a quality ADC
- High-resolution digital master created
From original magnetic media through professional playback and analogue-to-digital conversion to a digital preservation file.
02 · Digital capture
Sampling Rate & Bit Depth
Two of the most important technical choices in digital audio are how often the signal is sampled and how precisely its amplitude is represented.
Bit depth
How Precisely Levels Are Represented
Bit depth determines the number of possible amplitude levels. Professional preservation workflows commonly use 24-bit capture to provide substantial dynamic range and headroom.
03 · Channel configuration
Mono, Stereo & Multitrack Audio
The original channel configuration should be understood and preserved. A mono recording should not be treated as stereo, and multitrack material may require each track to remain independently accessible.
04 · Preservation masters
What Is Digital Audio Preservation?
Digital preservation is more than converting a tape into a file. A preservation workflow considers the capture specification, file format, naming, metadata, storage, backups, integrity and future access.
For archival projects, uncompressed PCM WAV or Broadcast Wave Format (BWF) is commonly used for high-quality preservation masters, with access copies created separately when required.
05 · File formats
WAV & Broadcast WAV (BWF)
WAV is a widely supported container for uncompressed PCM audio. Broadcast Wave Format (BWF) extends WAV with fields that can support professional metadata and broadcast/archive workflows.
WAV / WAVEBWFUncompressed PCM24-bit96 kHzMetadata
06 · Condition & treatment
Tape Deterioration & Tape Baking
Ageing magnetic tape can develop physical and chemical problems that affect playback. Assessment should come before attempting to play vulnerable recordings.
What Is Tape Deterioration?
Heat, humidity, age, poor storage, contamination and unstable binder formulations can contribute to sticky shed, oxide loss, mould, warping, shedding and other playback problems.
What Is Tape Baking?
For appropriate tapes affected by binder-related problems, controlled heating may temporarily stabilise the tape enough to allow safe playback and digitisation. Treatment should be assessed and undertaken carefully rather than applied routinely.
07 · Quality assurance
What Is Audio Digitisation Quality Control?
Quality control checks that the digital transfer is complete, technically correct and faithful to the original recording.
08 · Explore the Knowledge Centre
Audio Preservation Guides
Use the individual guides below when you need a deeper explanation of a particular audio preservation topic.
Technical specification
24-bit / 96 kHz Audio
Understanding a common high-resolution archival capture specification.
Read guide →
DigitisationAnalogue Audio Digitisation
How an analogue recording is converted into digital audio.
Read guide →
Digital audioAudio Bit Depth
How bit depth affects amplitude resolution and dynamic range.
Read guide →
ChannelsAudio Channel Format
Mono, stereo and multichannel recordings explained.
Read guide →
Quality assuranceAudio Digitisation Quality Control
Checks used to verify a reliable and accurate transfer.
Read guide →
Digital audioAudio Sampling Rate
Why sampling frequency matters when capturing analogue sound.
Read guide →
Media conditionAudio Tape Deterioration
Common causes, symptoms and playback risks.
Read guide →
File formatBroadcast Wave (BWF)
Understanding BWF and its role in professional audio workflows.
Read guide →
PreservationDigital Audio Preservation
Turning a transfer into a sustainable preservation workflow.
Read guide →
TreatmentTape Baking
When and why controlled tape treatment may be required.
Read guide →
File formatWAV Audio
Understanding WAV, uncompressed PCM and preservation files.
Read guide →
Recording formatMono, Stereo & Multitrack
How different channel arrangements affect preservation and delivery.
Read guide →
Have an Audio Collection That Needs Preserving?
From a single DAT or cassette to large broadcast and heritage collections, we can help identify the media, assess its condition and establish an appropriate digitisation specification.
Discuss Your Audio Collection →