Sony Dynamic Digital Sound (also known as SDDS) is a digital sound system for use in cinemas (ok, movie theaters for the Americans in here). It can be viewed as an enhancement to Dolby 5.1 / Dolby Digital.

Dolby Digital uses 5 location-specific channels, and a subwoofer. The 5 channels are:

  • Left (Front)
  • Centre (Front)
  • Right (Front)
  • Surround Left (Rear)
  • Surround Right (Read)

SDDS adds in two extra channels at the front to give more flexibility of where the sound appears to come from on the screen.

  • Left (Front)
  • Left-Centre (Front)
  • Centre (Front)
  • Right-Center (Front)
  • Right (Front)
  • Surround Left (Rear)
  • Surround Right (Read)

In large cinemas, this is definitely an improvement. Whether it makes any difference to a home cinema setup is questionable, as the main front left and right speakers are comparatively close together anyway - home cinema screens (aka televisions!) aren't that big!

Technically, SDDS sound is "recorded" optically on the edge of the film. Dolby Digital is placed between the sprocket holes, arguably the safest part of the film and most immune to damage. SDDS runs down the outside edges of the film, and is read with a laser, giving a much higher bandwidth. It is more susceptable to damage, being at the edge of the film - however, it is placed on both edges for redundancy, thereby reducing the risk.

Due to its different location on the film, it can co-exist with a Dolby Digital soundtrack, and indeed many films are released with both digital soundtracks present (and usually the timing pulses for DTS as well).

Log in or registerto write something here or to contact authors.