The Philips BT2500B is one among many inexpensive micro Bluetooth speakers to hit the market in the last couple of years. A lot of speakers of this type have more of a canister design to them, but what helps set this one apart is its relatively flat design, which makes it easy to slip into a bag or even a pocket. It's also modestly priced at around $45 online.
Though you can sit the speaker up vertically, it's really meant to be laid down flat with the driver firing upward. In that sense, it looks like a portable speakerphone and happens to offer that feature as well. I can't say the build quality or all-plastic design are all that swanky, but the speaker looks fairly attractive and has enough heft to it -- it weighs 7.7 ounces -- to steer it away from feeling cheap.
Like a lot of these little speakers, the 3.9x3.9x1.3-inch BT2500B plays louder than its size would indicate, and I liked the analog volume knob, which gives the speaker a slightly retro look and, more importantly, makes it easy to raise and lower the speaker's volume.
That same volume knob can be found on the step-up BT3500, which costs around $30 more and is essentially a double-wide version of the BT2500B. It adds NFC tap-to-pair technology for devices that support it, but otherwise the two speakers have identical feature sets and include the standard audio input for non-Bluetooth devices.
It's hard to say which speaker I like better. I thought they both sounded pretty good for their size, though as you'd expect, the larger BT3500 does sound a bit fuller and plays louder; it's clearly the better performer. However, I like the design of the smaller BT2500B. It's literally pocket-size.
These tiny Bluetooth speakers do have their sound limitations, so you shouldn't expect the world from them, particularly in the bass department (it's going to sound restrained with techno and hip-hop, for instance).
That said, I though the BT2500B managed to avoid sounding harsh and was relatively distortion-free, though it performs better at more modest volume levels and with less complicated music where you don't have a bunch of instruments playing all at once. It's designed for casual, not critical listening, and would also work well as an audio source for movies on a tablet or laptop.
It also performed fairly well as a speakerphone as long as I didn't wander too far away from the speaker's microphone while talking.
In terms of similar products I've reviewed, I'd say this is closest to the hockey-puck-size JBL Micro Wireless ($49.99), which a lot of people like. This Philips measures up well in terms of sound and adds the speakerphone capabilities, a nice plus. It's also comparable to the new Divoom Voombox Travel (also $49.99), which delivers similar sound but adds a "ruggedized" splash-proof body to the mix. Indeed, the rough-and-tumble Divoom looked a bit more durable than the Philips.
The BT2500 charges via Micro-USB and its battery life is rated at 5 hours (the BT3500 and JBL Micro Wireless are also rated at 5 hours, the Divoom at 6). You'd ideally like to have a speaker rated for at least 8 hours of listening, but if you don't crank the volume too much, you may be able to improve on that 5-hour number.
Mini Bluetooth speakers are a dime a dozen these days but some, including the Philips BT2500B, are better than others.
Its slim shape and compact footprint make it ideal for travel, and while it does have its sound limitations, its output is fairly impressive for its small size. No, it's not as swanky or sturdily built as the Jawbone Mini Jambox , but it costs a lot less, making it a good value choice in the mini Bluetooth speaker category.