Thursday, January 11, 2007

Home Theater system ; Dolby Digital, DTS

Delivers 5 audio channels and 1 LFE channel from a 6 channel source:

  • Two channels for speakers at the front - left (L) and right (R).
  • One channel for speaker at the center - center (C).
  • Two channels for surround speakers at the rear - surround left (LS) and surround right (RS).
  • One low-frequency channel using a sub-woofer (LFE).
  • Describes the Dolby and DTS Surround systems. Source media, usually DVD and
  • sometimes Laserdisc or satellite/digital cable is often branded with "Dolby Digital" and/or DTS logos.
  • DTS uses a higher sampling rate than Dolby Digital, thus DTS uses less compression and achieves higher fidelity than Dolby Digital.
  • Surround Sound speaker placement: (6 speakers in total) Surround Sound speaker placement is different for both music and movie content.

For music speakers are placed in a circle around the listener. The center channel has 0º offset, left and right are offset ± 30º, and the left/right surrounds are offset by ±110º. Also all speakers should be monopole, equidistant to the listener, and all delay (ms) calculations on the surround decoder should be turned off (0ms).


For movie surround, the front speakers should be placed at the edges of the screen, toed in to face the central listening location, and the tweeters should be ear height. The center speaker should be placed behind the screen (when using projection) or over or under a tv, and as close to ear high as possible. Rear channel speakers should be placed high on side walls, slightly behind the listening position, and should have a nomal hi quality monopolar construction.