Audio Video News

Onkyo's TX-SR607 surround receiver ($599) is the first from any manufacturer to include Dolby Pro Logic IIz, the new height-enhanced surround mode from Dolby Laboratories.

Dolby Pro Logic IIz adds a pair of height channels (and speakers) to the standard 5.1- or 7.1-channel array, for a total of 7.1 or 9.1 channels. The extra pair is placed above the front left and right to provide a feeling of height in the front of the soundfield. DPLIIz is not an encode/decode process like Dolby Digital or Dolby TrueHD. Instead, it acts on any kind of surround or stereo signal.

As Dolby explains in its DPLIIz primer:

Extensive listening sessions established that adding a height dimension to a home theater brings a greater sense of realism than would the addition of surround speakers in the horizontal plane to 7.1 systems. People are also far more sensitive to directional cues from sounds occurring in front than from those behind, determining that front speaker placement is ideal.

Expanding on established Dolby Pro Logic II matrix decoding innovations, Dolby Pro Logic IIz identifies and decodes spatial cues that occur naturally in all content—stereo and 5.1 broadcast, music CDs, DVDs, 5.1 and 7.1 Blu-ray discs, and video games. Dolby Pro Logic IIz processes low-level, uncorrelated information—such as ambience and some amorphous effects like rain or wind—and directs it to the front height speakers....

The enhanced spatial effects bring an overall airiness to the listening experience, a new dimension of presence and depth.

With Dolby Pro Logic IIz, rain in a movie now seems to be actually falling on the listener's roof, concert videos bring a more intense sense of being at the performance, and orchestral works deliver more palpable depth, power, and connection.

In games, the added dimension increases the realism and immerses players more deeply than ever in the action.

Though simple, small two-way speakers may suffice as height speakers, this seems to be a great opportunity for speaker manufacturers to get creative, building products specifically designed for the new technology. They might start with the question: "How am I going to mount a speaker way up there?" I would love to get some all-in-one front left/right speakers with top drivers that shoot the height channels at the ceiling. Just a suggestion.