Silene invisa cyme of up to three flowers at the top of the stem. Each flower has a bell-shaped calyx of fused sepals lined with ten green veins and covered in short, glandular hairs. The strap-shaped or rectangular petals have blunt tips or may be notched. They are whitish to pinkish or lavender and sometimes barely protrude from the calyx. Silene invisa Silene invisa is a species of flowering plant in the pink family known by the common names red fir catchfly and short-petaled campion. It is endemic to California, where it is known only from the southernmost Cascade Range and northernmost
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