Fundamentals

dBu

Definition

A voltage-referenced measurement unit used in professional analog audio equipment. 0 dBu equals 0.775 volts RMS. The standard operating level in professional studio gear is +4 dBu; consumer equipment typically operates at -10 dBV.

In Simple Terms

A measurement used by professional analog gear to describe signal level. Most relevant if you're connecting hardware equipment together, mismatching levels between pro and consumer gear creates noise or distortion.

Common Confusion

dBu and dBV are both voltage references but use different zero points. Mismatching equipment operating levels is a common source of unexpected noise or distortion in hybrid analog/digital setups.

Sources & Verification

  • IEC 60268-15. Sound system equipment. Part 15: Preferred matching values for the interconnection of sound system components
    International Electrotechnical Commission
  • AES48-2005. AES standard on interconnections. Grounding and EMC practices
    Audio Engineering Society

Last verified: 2026-05-04

Related Terms

dBdBFSSignal ChainAnalogGain Staging
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