The Flip 4 doesn't look very different from it predecessors. At 6.9 x 2.75 inches, the cylindrical speaker is a touch longer and taller than the Flip 3, but you can't tell just by looking. The biggest aesthetic change is that the endcaps are encased in plastic, adding to the unit's ruggedness.
It comes in several colors: black, red, white, blue, gray and teal — though that's actually fewer options than the Flip 3 offered. If the Flip is too staid for you, check out the Roll 2, which offers much wilder colors.
The speaker has volume controls, a Bluetooth-pairing button and a play button, which also advances to the next track if you press it twice quickly. On the back, you'll find the power button, a battery-life indicator and a button to connect to other JBL speakers. Under a flap, there's the micro USB port for charging the battery and a 3.5mm input jack.
The Flip 4 overcomes the typical trade-offs that a relatively small speaker makes. Instead of weak bass and lifeless vocals, the new Flip wows with thumping low end, full midtones and crisp treble. The Flip 3 was already one of the best-sounding speakers selling for $100, and the Flip 4 sounds better in all ways.
Rihanna's vocals on Future's "Selfish" came through full and clear, while the bass on the track thumped without being muddy. I could hear the details in the distorted guitars on Japandroids' "Near to the Wild Heart of Life," while that song on the UE Roll 2 sounded less clear.
The Flip 4 performed well on acoustic music, too: Lindsey Buckingham's acoustic guitar on Fleetwood Mac's "Never Going Back Again" was crisp, while Miles Davis' trumpet on "Summertime" was bright and full.
The Flip 4 gets plenty loud for most settings; I measured it at above 90 decibels at max. But pushing it above 85 decibels distorts the sound badly. The Roll 2 can also crank the volume, so that shouldn't be a deciding factor in which speaker you get.
The Flip 3 added water resistance, but it trailed the Roll 2 in overall ruggedness. The Flip 4 fixes that, matching the Roll 2's IPX7 rating, meaning it can be submerged in up to 1 meter of water for 30 minutes. I dunked it in a sinkful of water for 5 minutes, and the unit continued to perform well.
JBL states that the Flip 4's battery life at 12 hours, but that seems low. After I spent more than 6 hours listening, the battery indicator showed it still had four-fifths of the charge left. The Flip 3's battery was rated at 10 hours, while the Roll 2 advertises 9 hours of playback on a charge.
Like the Flip 3, the Flip comes with an excellent speakerphone, something the Roll 2 lacks entirely. People I spoke to said my voice was fuller compared to on the iPhone's built-in speakerphone, while the richness of the speaker drivers made it easier for me to understand the people on the other end of the line.
MORE: Best outdoor speakers
Wireless and Setup
The unit paired quickly over Bluetooth. It has excellent range, maintaining a strong connection at more than 50 feet indoors.
There's little to do beyond turning it on and pressing play. JBL's free Connect app for iOS and Android adds some tweaks you can make, like changing the Play button to activate Hey, Siri or Google Now. But it doesn't include an equalizer, an alarm or the other functions that make UE's app stand out.
You can also use JBL's Connect+ technology to pair the Flip 4 with other JBL speakers that support Connect+ for more fidelity or to create a left-right stereo system.
User Reviews: What Owners Are Saying
The JBL Flip 4 isn't just a critical darling -- shoppers love it, too. At the time of this writing, the Flip 4 has an average rating of 4.5 out of 5 on Amazon out of a whopping 4,261 user reviews. Customers have near-universally praised the Flip 4's sound quality, battery life and durable design, though some shoppers found the bass to be a little soft. The speaker is also sitting at a 4.7 out of 5 out of the 2,700-plus user reviews on Best Buy. While you should always take user reviews with a grain of salt, there seems to be a pretty solid consensus on the Flip 4's quality.
With the improvements JBL made to the Flip 4, you no longer need to choose between sound quality and features in a $100 Bluetooth speaker. You can have it all.
The Flip 4's sound is impressive, with big bass and full vocals. And now that it's waterproof, you don't have to think twice about where you take it. Add in the improved battery and excellent speakerphone, and there's little to complain about. The UE Roll 2 has a more fun design, with a more interesting shape and splashier color choices. But for most people, the Flip 4 is now the best choice in this price range.