UE says the speaker has a range of about 50 feet, which is better than the usual 33 feet that your typical Bluetooth speaker is rated for. But outside 50 feet isn't as far as you think; the connection with my iPhone 4S started to break up when I walked off into the yard with my phone (I looked back at the speaker on the patio and calculated that yes, indeed, I was at right around the 50-foot mark give or take a few feet). I also tested it with a Samsung Galaxy S4 and achieved similar range.
The speaker will remember up to eight devices it's been paired with, which makes it easier to make a connection once you've set up the initial pairing. And while there's currently no aptX support, company reps said that could be added at some point through a software upgrade. (Certain smartphones, such as the Samsung's Galaxy S3 and S4, support aptX streaming, which allegedly offers better sound quality for Bluetooth transmission, though it matters less with smaller speakers such as the Boom.)
There's also NFC support -- sometimes referred to as "tap-to-pair" -- which works with certain smartphones, such as the Samsung Galaxy S3 and S4. It helps make pairing a device easier, but it really doesn't save any time.
I've listened to a lot of these compact Bluetooth speakers and the Boom plays very loud for its size. If it has a deficiency, it just doesn't deliver a ton of bass, though few if any of these small speakers put out great low end. You'll also get some distortion with bass-heavy material, particularly at louder volumes, and while it's got a bit more dynamic range and fuller sound than speakers such as the JBL Flip and Charge, it's not a huge advantage.
The speaker offers decent though not exceptional clarity and like most of these small speakers, it's strongest in the midrange, so it sounds best with acoustic tracks.
As I hinted in the intro, I listened with a more critical ear indoors, where the speaker's limitations are more apparent. Outdoor listening is a different ballgame. You're dealing with wind and ambient noise and what a lot of folks are looking for is a portable speaker that can play loud and sound decent doing it -- and that's just what the Boom can do. It easily bests the Jawbone Jambox, which just isn't well suited for outdoor use -- especially if it's windy. It can also play louder than the JBL Flip and Charge and seems more durable than those models (no carrying case is included because UE says the speaker can hack it unprotected). It also has better battery life.
As far as speakerphone performance goes, it seemed good. If it's windy outside, people will have hard time hearing you, but when I set the speaker in the middle of large table on the patio on a windless day, my children and I were able to have a conversation with their grandparents without a problem. We could hear them fine and they said we sounded "pretty clear."
And what about combining two Booms? Well, if you can afford it, you'll definitely get augmented sound -- with the same flaws (the bass doesn't sound any fuller). I'd say the left/right configuration works a little better indoors (it's nice to get some stereo separation), but I found myself gravitating toward the double mono setup outdoors to widen the footprint of the speakers, so to speak.
The UE Boom is one those products that grows on you the more you use it. Judging it purely from an audiophile perspective, it has some shortcomings, particularly in the bass department. But on a less nitpicky level, it's a well-designed compact speaker with sleek looks, good build quality, and long battery life. It also happens to be water- and stain-resistant, making you more confident about taking it places -- and perching it in spots -- that might seem a little precarious for other speakers.
Where the speaker excels is outdoor use. If you trot it out at the next barbecue, you're sure to get a guest or two asking what company makes it and what it costs. Yeah, it's a bit pricey at $200, but once you use it for a while, I don't think you'll regret buying it. It bests our recent outdoor Bluetooth favorite, the Grace Digital Ecoxgear Ecoxbt, on nearly every front -- design, features, audio quality, and battery life -- except for price.
Of course, if you have any doubts about the Logitech, buy it from a place that has a decent return policy and give it a test run yourself. Just make sure to try it indoors and outdoors before you make your final decision.