- Great Painters
- Accounting
- Fundamentals of Law
- Marketing
- Shorthand
- Concept Cars
- Videogames
- The World of Sports

- Blogs
- Free Software
- Google
- My Computer

- PHP Language and Applications
- Wikipedia
- Windows Vista

- Education
- Masterpieces of English Literature
- American English

- English Dictionaries
- The English Language

- Medical Emergencies
- The Theory of Memory
- The Beatles
- Dances
- Microphones
- Musical Notation
- Music Instruments
- Batteries
- Nanotechnology
- Cosmetics
- Diets
- Vegetarianism and Veganism
- Christmas Traditions
- Animals

- Fruits And Vegetables


  1. Acoustics
  2. AKG Acoustics
  3. Audio feedback
  4. Audio level compression
  5. Audio quality measurement
  6. Audio-Technica
  7. Balanced audio connector
  8. Beyerdynamic
  9. Blumlein Pair
  10. Capacitor
  11. Carbon microphone
  12. Clipping
  13. Contact microphone
  14. Crosstalk measurement
  15. DB
  16. Decibel
  17. Directional microphone
  18. Dynamic range
  19. Earthworks
  20. Electret microphone
  21. Electrical impedance
  22. Electro-Voice
  23. Equal-loudness contour
  24. Frequency response
  25. Georg Neumann
  26. Harmonic distortion
  27. Headroom
  28. ITU-R 468 noise weighting
  29. Jecklin Disk
  30. Laser microphone
  31. Lavalier microphone
  32. Loudspeaker
  33. M-Audio
  34. Microphone
  35. Microphone array
  36. Microphone practice
  37. Microphone stand
  38. Microphonics
  39. Nevaton
  40. Noise
  41. Noise health effects
  42. Nominal impedance
  43. NOS stereo technique
  44. ORTF stereo technique
  45. Parabolic microphone
  46. Peak signal-to-noise ratio
  47. Phantom power
  48. Pop filter
  49. Positive feedback
  50. Rode
  51. Ribbon microphone
  52. Schoeps
  53. Sennheiser
  54. Shock mount
  55. Shure
  56. Shure SM58
  57. Signal-to-noise ratio
  58. Soundfield microphone
  59. Sound level meter
  60. Sound pressure
  61. Sound pressure level
  62. Total harmonic distortion
  63. U 47
  64. Wireless microphone
  65. XLR connector



This article is from:

All text is available under the terms of the GNU Free Documentation License: 


From Wikipedia, the free encyclopedia

This article is about the audio signal processing term. For other uses, see Headroom (disambiguation).

Headroom is a term used in signal processing referring to the maximum allowable signal level before compression or distortion.

In an audio system headroom is the amount by which the maximum permitted level, or digital FS (full scale) exceeds the alignment level, in dB (decibels). Alignment level is an 'anchor' point, a reference level that exists throughout the system or broadcast chain, though it may have different actual voltage levels at different points. Typically though, alignment level is +4 dBu at analog points in a professional audio chain, or 0 dBu in a broadcast audio chain, and −18 dB FS at digital points, corresponding to 18 dB of headroom, the EBU recommended figure for digital recordings. An alternative EBU recommendation allows 24 dB of headroom, which might be used for 24-bit master recordings, where it is useful to allow more room for unexpected peaks during the live recording process.

Failure to provide adequate headroom is a common problem with CD's published in the late 1990s and early 2000s which often use heavy level compression (not to be confused with data compression by codecs such as MP3), producing a very flat 'mushy' sound that lacks the sparkle provided by brief peaks from percussion sounds.[citation needed] See Loudness war.

See also

  • Audio quality measurement
  • Noise measurement
  • Programme levels
  • Rumble measurement
  • ITU-R 468 noise weighting
  • A-weighting
  • Weighting filter
  • Equal-loudness contour
  • Fletcher-Munson curves

External links

  • EBU Recommendation R68-2000
  • AES Preprint 4828 - Levels in Digital Audio Broadcasting by Neil Gilchrist (not free)
  • EBU Recommendation R117-2006 (against loudness war)
  • AES Convention Paper 5538 On Levelling and Loudness Problems at Broadcast Studios
  • EBU Tech 3282-E on EBU RDAT Tape Levels
  • EBU R89-1997 on CD-R levels
  • AES17-1998 (r2004): AES standard method for digital audio engineering -- Measurement of digital audio equipment
Retrieved from ""