NOT a subwoofer, the SoundTube LA808i is designed to increase the directivity of low frequencies in SoundTube’s Line Array system. It can be used only in conjuction with the LA880i 3-way line array. The use of the LA808i is recommended in spaces that have a large reverberation time. When a single unit is added to the LA880i, directivity of low frequencies is increased by up to an octave lower than with the LA880i alone. The product’s dimensions are identical to those of the LA880i. The LA808i must be placed either directly above or directly below the LA880i in order for the system to work properly. If desired, two LA808i units can be added: one above the LA880i and one below.