Answer

The model DCA1222 cinema amplifier is particularly well-suited for surround loudspeakers. First, its power rating is a good match for surrounds, while the higher-power DCA models are well matched for the high-power needs of screen channels.

But there is more to it. Auditoriums will often have five surround loudspeakers per amplifier channel. Installers often resort to series-parallel wiring schemes of 8Ω loudspeakers to avoid placing a 2Ω or lower load on the amplifier. That is usually unnecessary with the DCA1222. The model has the same heat sink and fan as the other DCA Series models, but it is also the lowest-power model, so its ratio of cooling capacity to heat dissipation is quite favorable for driving low load impedances.

Therefore, the DCA1222 is recommended for driving five 8Ω loudspeakers per channel because they can be wired in parallel—which makes better use of the amplifier's power capability and offers better sound quality—with much lower risk of overheating the amplifier.

The other DCA Series amplifier models and the ISA Series amplifier models are not as tolerant of load impedances under 2Ω and are not recommended for this application.