Three models cover a complete cinema.
From a compact dedicated room up to a screening room or a venue theatre. What changes is how many of each, and whether the front array steps up to the 12 or stays with the 8.
Channel counts, placement angles and subwoofer positions depend on the room's dimensions, seating rows and screen type. They are worked out as part of the room design rather than read off a table.
Front LCR
Matterhorn 12
The flagship front channel, a sealed two-way coaxial on a twelve-inch woofer and intended for matched left, centre and right duty behind an acoustically transparent screen.
Surround · Compact LCR
Matterhorn 8
Two roles in one cabinet: surround and surround back alongside the 12 in a large room, or front LCR in its own right in a smaller one.
Subwoofer
Matterhorn 18S
An eighteen-inch drive unit in a sealed enclosure, carrying the LFE channel and bass-managed content from every other channel.
A typical room.
A medium to large dedicated cinema usually runs three Matterhorn 12 as front LCR, Matterhorn 8 for surround and surround back duty, and at least two Matterhorn 18S.
In a smaller dedicated room the Matterhorn 8 can take the front LCR role instead, with the same voicing carried through. The right answer depends on dimensions, seating layout and screen type — which is why it is worked out as part of the room design rather than chosen from a catalogue.