Streptanthus albidus smaller and narrower, sometimes linear in shape, and toothed or smooth-edged. Flowers occur at intervals along the upper stem. Each has a spherical to urn-shaped calyx of keeled sepals about a centimeter long with curving petals emerging from the tip. The calyx of sepals may be white to purple, depending on subspecies. The fruit is a long, narrow silique which may be 12 centimeters in length. There are two subspecies, both rare. Streptanthus albidus Streptanthus albidus is a species of flowering plant in the mustard family known by the common name Metcalf Canyon jewelflower. It is endemic to California, where
Surround channels strictly diffuse. Optimally there should be discrete surround channels for diffuse and direct effects. This is part of the design for Tomlinson Holman's 10.2 surround sound. For movies surround channel information is usually more diffuse ambient noise. Some surround sound systems such as Dolby Digital EX and Pro Logic IIx incorporate a third (back surround) or even fourth surround channel (back left and back right). These channels are "matrixed" from the standard surround channels; they are not discrete. Some matrix encoding surround sound systems use a single back center channel surround (Dolby Digital EX, Dolby Pro Logic IIx 6.1) or