How can I upgrade my THX system to a 7.1 sound format?

With the THX 7.1 amplifiers/receivers, there is always the option of connecting two rear centre speakers. We would also recommend using four rear speakers. Due to the elaborate development of our rear speakers, our models can be used very flexibly for any application. Here we have to differentiate as follows: - You have a THX Select/Ultra 2 device and want to connect two rear centre speakers: if you already use dipoles or direct radiators in your 5.1 system, you have the choice of adding either two more dipoles or two direct radiators as rear centres. For wall mounting and/or at a short distance from seat to rear wall (less than 1.00 m), we would recommend dipoles that are also operated in dipole mode (for System 4 THX, for example, order 2 x additional S 400 D). As soon as you want to place the speaker on stands or on a shelf, we would recommend direct radiators (for System 4 THX, e.g. order 2 x additional S 400 FCR). As soon as you already use direct radiators with your 5.1 system, we would recommend the same type of direct radiators for the upgrade. You have a THX Ultra 2 unit and want to connect two rear centres: a circuit especially developed for THX Ultra 2 devices allows you to use two more direct radiators or two more dipoles in addition to the dipoles used as rear effect loudspeakers.