prices on 2 models
9.1
— of the nine full-frequency channels provided in this format, five correspond to the 5.1 format (centre, left / right front, left / right rear), and four more can be placed in a variety of ways, up to directing to the ceiling. Anyway, this format provides a very accurate transmission of multi-channel audio, but it is expensive, difficult to set up, and there is very little specialized content for it.