The PSB Imagine T2 stereo loudspeakers conform, stylistically and engineering-wise, to the current conventions. They are very slim (just 190mm across the widest part of their curved bodies), and, rather than having one big woofer, they have several small ones. Three, in fact; each 133mm (5.25 inches in the old system).
These bass drivers are lined up vertically, of course, but are quite widely spread on the bottom three quarters of the enclosure. The reason is that each has its own separate enclosure within the case. The cabinets are bass-reflex designed, so there are three ports on the rear, one for each of the three internal enclosures. Each speaker comes with one rubber plug, which you can use to close one of the ports to tune the bass (plugging the port reduces the peak output significantly, but also tends to extend the deeper bass).
At the top of the enclosure is a 102mm mid-range driver, and just underneath it and above the uppermost bass driver is a 25mm titanium dome tweeter. With the speaker mounted on the supplied spikes (which screw into small side extensions at the bottom of the speaker), the centre of the tweeter is about 860mm from the ground, which is a little below ear level for a normal couch-seated listener.
The four larger drivers all look similar at first glance, except for size, but they are, in fact, quite different. Unlike the mid-range, the three woofers have fixed "phase plugs". That is, while the surrounding cone of the woofers vibrates, these machined cones remain stationary. The purpose of these is to reduce distortion caused by the higher frequencies produced near the centre of the cones from interfering with each other.
A removable cloth grille covers the front of each loudspeaker, and gives exceptional protection, since it was backed by a perforated metal grille.