Angelica acutiloba with distinct calyx and white corolla. However, the calyx is often reduced with obsolete calyx teeth. The flowers have five petals, sepals, and stamens. The white petals are often obovate to oblong. The inflorescences contain fifteen to forty-five pubescent rays, 1–10 cm in length, which surround about thirty small disk flowers. The peduncles which hold the entire inflorescence are glabrous or pubescent and 5–20 cm long. While the stalks of each single flower in the flower clusters called pedicels, are thin and often sessile. The whorl of bracts beneath the inflorescences is called involucre. It consists of phyllaries, modified bracts,
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