The UE Boom has been a mainstay at the top of CNET's best portable Bluetooth speakers list the past couple of years, so we were very curious to see what UE (Ultimate Ears) had in store for its successor, the UE Boom 2, which retails for $200 (£170; AU$250). Like all such Bluetooth speakers, the UE Boom 2 allows you to stream audio from nearly any smartphone or tablet, regardless of the source app or operating system.

On the outside, at least, not much has changed. That's because the two speakers look very similar, although there are some small but important cosmetic changes. The new model, which comes in six color options at launch, has a tighter weave on the fabric cover, making it more durable. Also, the flap that covers the ports is now better integrated into the unit with a groove in the top of the speaker that makes everything flush.

The other external change is the degree of weatherproofing. The original was water resistant, but this model is fully waterproof (iPX7 -- immersion up to 1 m for 30 minutes), as well as drop-resistant to five feet or 1.5 meters. UE says that even if you forget to close that little flap that covers the USB charging port and audio input, you don't have to worry about any water getting inside the speaker.

Enlarge Image Sarah Tew/CNET

All the other changes are on the inside. UE has completely redesigned the driver so the speaker not only sounds a little better than the original but also plays 25 percent louder at its top volume. That said, like all these compact Bluetooth speakers, it still distorts a bit at higher volumes with certain tracks, but most people will be very impressed with how loudly the speaker plays for its size and that it's able to deliver as full sound as it does (more on that in a minute).

While the driver is heavier in the new model, UE took out a hidden weight that helped the original Boom balance itself when lying down in horizontal mode. With the weight gone, at 548 grams or 19.3 ounces the Boom 2 weighs just a few grams more than the old Boom.

UE's also added gesture controls -- you tap the top of the speaker to pause your music and double-tap to skip a track forward (you have to be holding the speaker in your hand to use the gesture controls).

Enlarge Image Sarah Tew/CNET

Other new features included the ability to update the speaker's firmware over the air via UE's new app instead of having to connect the speaker to a computer. You can also turn the speaker on and off via the app instead of going over to the speaker and pressing the power button on top. Nice.