As mentioned above, the second compatible app available is Music Mix; you use it for playing music when you dock two iPhones or iPod Touches. You launch the app on your Touch or iPhone, then dock your second Apple music player and the app links your two music players and shuffles your music--we had a little trouble getting our iPod Touch to link up with an iPhone, but after docking it a couple of times, they finally joined up. You only need to install the app on one of the two docked players.
Once linked, you can decide how much you want to listen to the songs on each device by adjusting a virtual slider from within the app. For instance, if you don't want to insult a significant other who has an iPod docked next to yours, you can set the slider to 50 percent, the midway point. But if you're as bold as to prefer your music, you can move the slider accordingly, adjusting the slider to the right or left, depending on which dock your player is in. Whether it's cool or a bit silly is something you'll have to determine.
The Octiv Mini has no buttons to speak of--you have to control everything through your iPod or iPhone--but Altec has put some buttons on the Duo. The "source" button lets you choose between the left and right docks or the auxiliary input on the back (yes, you can connect other audio devices with an optional cable). It also has buttons for power and volume.
Altec also includes a small circular remote for controlling the basic functions of your iPod or iPhone. What's nifty about the remote control is that it adheres magnetically to a spot on the back of the unit so you can stow it for safekeeping. You wouldn't even know it's there unless you looked. However, its circular shape is unusual, and the button layout takes a bit of getting used to.
In terms of sound, this is definitely a step up from the mono (read: no stereo) Octiv and a bigger step up from your typical clock radio. But don't expect to get the kind of detail or bass that you'd get from more-expensive, larger iPod-iPhone speaker systems. Also, because the speaker is so small, you shouldn't expect much in the way of stereo separation.
Still, for a small speaker, the sound is decent enough, and there's just enough bass and clarity to make you say to yourself, "This thing sound OK," which is a compliment for a $99 speaker. It's also worth noting that this little guy plays fairly loud and is a good fit for a bedroom, kitchen, bathroom, and other places where you don't do your critical listening. (As we said in our Octiv Mini review, we ended up listening to a lot of Pandora radio and it's certainly well suited to lower-bit-rate music because it doesn't accentuate its flaws like some higher-end speakers do).
As for price, in this range, the Octiv Duo faces a lot of competition. But its dual docks, the unit's compact size, decent sound and styling, along with the included remote, and app-enhancing features--not to mention that useful extra USB power up--give the Duo enough distinguishing traits to make us recommend it.