The Cub2 sub sounds good, producing bass that is fairly tight, with none of the exaggerated "woomph" that comes with some bass-reflex designs, and that offers sufficiently good transient speed to blend well with the Sibs. The sub also has enough output to give the floor a nice shake, though it doesn't go to serious depths that you can feel in your gut. Even so, I could never get over the feeling that the strong treble and midrange presence of the Sibs demanded an even stronger subwoofer. While the Cub2 is actually one of the nicer small subwoofers I have heard, I think the Sib XXLs need an even more forceful subwoofer. A Cub XXL perhaps?
On music, I tried the system both in 2.1- and 5.1-channel configurations and preferred the latter, in particular for listening to stereo material using either Dolby Pro Logic II or other similar surround decoding systems. Overall, the 5.1-channel configuration sounded fuller, more dynamic, open and airy, and by distributing the volume of the music across more speakers the 5.1- channel configuration also minimized that residual bit of harshness from the aluminum tweeters. I compared 2.1- channel vs. 5.1-channel versions of the system on Massive Attack's "Teardrop" [Teardrop, Virgin]—a track that begins with a significant amount of bass and then breaks into the sound of synthesizers and vocals. In 2.1-channel mode, the Sib/Cub system made the lower midrange of the vocals sound recessed, while the tweeters showed their bit of harshness during the keyboard sections. The 2.1-channel configuration just didn't have sufficient power to capture the full dynamic range of which this track is capable. But when I activated a surround sound mode such as Dolby Pro Logic II and brought 5.1-channels into play, the system immediately became much more dynamic and cohesive. Treble harshness decreased even as the midrange—especially the lower midrange—became more fully fleshed-out, making the synthesizer sound smoother and the vocals sound warmer and more natural.
For movies the 5.1-channel system proved very good indeed, providing clarity and dynamics, and even a bit of punch from the subwoofer. This was demonstrated ably in Ronin [MGM/United Artists], where the explosions and car chases allowed these speakers to really open up and display the inherent clarity of their midrange as well as their ability to create a believable, three-dimensional sonic bubble during the car chase sequences. When there is so much going on in an action sequence, it is easy for a speaker system to get muddled and lose clarity, but the Sib/Cub system held its own. The relatively limited 40Hz reach of the Cub is soon forgotten when the little sub shakes the floor during explosions, and it becomes obvious that this system can fill a moderately sized room.
More than anything else, this system combines strong visual design aesthetics with much better than average sound quality—something many other "lifestyle" systems fail to do. For those looking for a well-built, compact and attractive system that can fill a moderately large room with dynamic sound, this system absolutely deserves an audition.