The "killer feature" of the Fidelio 7700 is portability, and it delivers that in spades. Weighing in at around 750g, it feels almost too light to be a "real" speaker. By comparison, the Fidelio 8500 weighs over 2.5kg — quite a significant difference.
But you do pay a price for that portability, and we don't just mean the AU$270+ you shell out to take one home. If you're expecting the Fidelio 7700 to match the sound quality of the Fidelio 8500 series with its full-range speakers and SoundCurve enhancement, you'll be disappointed. However, if you expect the Fidelio 7700 to sound like other speakers of this size, then you'll be pleasantly surprised.
The Fidelio makes up for its smaller size with a bit of electronic fiddling via Dynamic Bass Boost (DBB). DBB essentially compensates for the poor bass performance of speakers this size at low volumes by artificially upping the bass. As you might expect, this works better with some types of music than it does with others.
One area where it works quite well is in gaming. As well as the standard 30-pin dock connector, the Fidelio 7700 can connect to your iPad via Bluetooth, so you can use it to boost the iPad's anaemic little built-in speaker when playing games. Headphones are better for first-person shooters and the like, but for any game that you want other people to be able to hear comfortably (multi-player pass-and-play titles, for instance) it's quite an improvement.