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 Surround channels Surround channels are audio channels in surround sound multichannel audio. They primarily serve to deliver ambience and diffuse sounds in a film or music soundtrack. Dolby Stereo (1975) was the first standard cinema sound system using a single matrixed mono rear channel (note Disney's Fantasound from the 1930s used a surround channel). Dolby Surround (1982) was the first home audio system to use a rear channel. It and its successor, Dolby Pro Logic (1987), used a single rear surround channel, but often using two speakers connected in anti-phase or a dipole radiator, as shown in the speaker configuration