In the case of the "Crossover-free design for coherent, lifelike sound" they are talking about the speaker's internal components - where most speakers use an array of drivers (tweeter for high frequency, one or more 3" to 6" drivers for mid- and lower frequencies, and sometimes even more drivers for low frequencies) with an analog crossover circuit inside the speaker to divide the signal up between the appropriate drivers, the MOD1 and MOD2 use one or two 3" drivers that get the full signal with no internal crossover circuit. This arrangement is actually extremely rare outside of bargain-bin "home theater in a box" packages, and difficult to carry off well because a single driver is being asked to cover a wide frequency range.
The specs for the speakers are somewhat difficult to find (there's a
Specifications page linked part way down the left edge of the page), but if you look at the information for the MOD1 and MOD2 speakers by themselves it lists the -3dB response as 120Hz-18,000Hz and the -6dB response (which is much less commonly used, as 6dB represents a pretty significant dropoff) as 80Hz-20,000Hz.
The most notorious example of the single driver, no crossover design is the Bose Acoustimass line. Having sadly owned such a setup at one time, I'm pretty keenly aware of the opportunity for trouble with such a setup. Bose does not publish any frequency response data for the Acoustimass line, so I was pleased to see Orb providing that information. The Orbs do start to roll off in the treble a bit earlier than I'd like, but they get a lot higher than Bose's cubes (which some third-party testing has indicated roll off at 13,000Hz, a full 7,000Hz below the upper limit of human hearing).