The Magellan Concerto is a single-box speaker with three 6.5" bass drivers and a port, these located below unusually high-set, twinned midrange and treble drivers mounted on both the front and rear panels.
The Concerto will give good in-room balance in rooms of small to medium size. The idea of placing the mid and treble drivers significantly above the listener's seated head height is unconventional, but it works very well, giving the Concerto some extra scale and air without ever making the music seem out of place or perspective.
Some of that extra air and spaciousness is undoubtedly down to those additional rear-facing mid and treble drivers. Such an arrangement is sometimes called bipolar, though in the lateral plane at least it's really just a variation on the omnidirectional theme. A box-type (monopole) loudspeaker is naturally and inevitably omnidirectional at low frequencies, while the mid and treble are much more directional—especially the treble, and even more so when it's horn-loaded. Placing two drive-units back to back, as in the Concerto, effectively gives the midrange and treble an all-round distribution broadly similar to the bass.
Beautifully finished in a rich burr walnut pattern, the Magellan Concerto's tall, port-loaded enclosure has convex sides that are wider in the middle than at the front and back. This keeps the front and rear panels slim while maintaining decent internal volume. The curves will also tend to spread and defocus internal standing waves and, aided by internal bracing, stiffen the sides.
The unusual drive-units represent Triangle's unique philosophy. The three 6.5" cast-frame bass drivers are the most conventional, with flared paper cones equipped with powerful motors and exclusive S-shaped rubber surrounds (to aid large excursion). The midrange drivers also have 6.5" cast chassis and paper cones, but these cones are significantly smaller and the surrounds are much wider, "double-S" affairs made from doped fabric. This acknowledges that there's no need for large excursion here, and if fabric is less effective than rubber at absorbing energy, it also avoids the energy storage due to the latter's hysteresis. A small wooden "bullet" phase plug extends the central polepiece.