IEC 61606-1:2009

Overview

IEC 61606-1:2009 - "Audio and audiovisual equipment - Digital audio parts - Basic measurement methods of audio characteristics - Part 1: General" defines common, general measurement methods for the digital audio portions of audio and audiovisual equipment. It applies to consumer, professional and personal computer equipment where audio is handled as digital data and the audio bandwidth is approximately one-half of the system sampling frequency (typical sampling frequencies ≥ 32 kHz). Examples include CD players, DAT recorders, digital amplifiers, digital broadcast receivers and TV receivers with digital audio. The standard covers tests for devices with digital input / analogue output and analogue input / digital output (digital-in/digital-out and analogue-in/analogue-out tests are planned for future revisions).

Key topics and technical requirements

• Scope and exclusions: Applies to basic measurement methods of digital audio parts; does not apply to lossy compression signals or power amplifiers.
• Measuring conditions: Specifies environmental conditions, power-supply requirements (voltage, frequency, ripple), test signal frequencies and standard control settings for the equipment under test (EUT).
• Preconditioning: Defines preconditioning procedures and includes a changed period of preconditioning in this edition.
• Measuring instruments: Requirements for signal generators, filters (including newly added A-weighting filter), level meters, distortion meters, frequency and group-delay meters, spectrum/analyzer and digital waveform monitors.
• Measurement methods:
  • Digital-in / analogue-out: input/output characteristics, frequency response, group delay (phase linearity), noise (SNR, dynamic range, out-of-band noise), channel separation, distortion and intermodulation.
  • Analogue-in / digital-out: analogue-to-digital calibration, maximum input amplitude, folded noise, cross-talk, and similar distortion/noise tests.
• Terminology and metrics: Defines terms (including an explanation of jitter) and rated values needed for consistent testing.

Applications and who uses it

• Manufacturers of digital audio equipment for product design, validation and production test.
• Test laboratories and QA teams performing standardized performance verification and benchmarking.
• Audio engineers and system integrators validating measurement results for digital-to-analog and analog-to-digital stages.
• Broadcasters and receiver manufacturers ensuring compliance with digital sound performance criteria. Using IEC 61606-1 helps ensure repeatable, comparable measurements of digital audio characteristics across devices and platforms.

Related standards

• IEC 61606 (series) - Parts 2 (consumer), 3 (professional), 4 (personal computer)
• IEC 60268-3 - Amplifiers (related measurement methods)
• IEC 60958 - Digital audio interface
• AES17 and EIAJ CP-2i50 - referenced for certain test types and harmonization efforts

Keywords: IEC 61606-1:2009, digital audio measurement, audio characteristics, D/A, A/D, measurement methods, A-weighting, jitter, sampling frequency.