With all its SoundLink wireless speaker products product, Bose talks about the engineering challenges of getting good sound out of a very compact speaker, and a Bluetooth one at that, as Bluetooth compression diminishes sound quality.
With previous versions, you could debate whether the Bose sounded better than competing $300 portable Bluetooth speakers from the likes of Jawbone (the Big Jambox), Sony, and others. However, what was clear -- and remains clear with this model -- is that for their small size these Bose speakers perform very well, playing much louder and capable of producing more bass than they appear.
The goal with the SoundLink III was to get the speaker to play even louder (without distorting) and also sound a little better in the process. As always, getting there requires the finessing of both the hardware and the software that processes the sound and shapes it in a way that makes your ears think it sounds good (there's a bit of trickery involved, especially with a speaker that has little-to-no stereo separation).
Mission accomplished with the III; though all these small speakers have their limitations and the SoundLink III is no exception. The bass is slightly fuller and the overall sound slightly more detailed. And the speaker performs quite well with a lot of material but not everything.
Where it does best is with well-recorded, simpler tracks. The midrange is pretty forward so vocals stand out and acoustical tracks sound clean and dynamic (Sting's the Last Ship and The Rolling Stone' Hot Rocks came across well, for example). It sounded good with jazz and some rock material and it handled Nirvana's "All Apologies" as well as some bigger Bluetooth speakers. But with complicated material (a lot of instruments playing at the same time), you'll lose some definition (it did OK with Arcade Fire's Reflektor album but it sounds a lot better through a good pair of $300 headphones).
As far as the volume goes, it really does play loud -- it can fill a small- to medium-sized room, though it's a bit directional (stand off to the side and the sound quality diminishes).
It plays louder than its predecessors and doesn't distort at higher volumes, though to steer clear of distortion it rolls off the bass and sounds like it's restraining itself to keep from going off a cliff. Pop tracks like Ellie Goulding's "Burn" sounded pretty punchy and relatively clean. But it was hit or miss with techno tracks. The bass can sometimes seem a little subdued at higher volumes, so just don't expect real thumping bass with a lot of oomph to it. Then again, as I've said before, it's just not fair to expect subwoofer-level performance from a speaker the size of a hardcover book.
The reality is the SoundLink III is designed to play at more modest volume levels (it sounds best when it isn't pushed) and I think it offers a more detail and bass at lower volumes than its predecessors. In other words, it seems to sound a little richer at lower volumes, which is a good thing because that's how a lot of folks end up using this speaker -- as a background music generator.
If you're looking for a better value for quality casual listening, there's plenty of other stuff out there in the $150 range that does a good job (the, for example). In the $200 to $300 range, I also like the and , as well as the aforementioned Big Jambox.
But you'll be hard-pressed to find a Bluetooth speaker that's as compact as the SoundLink III and sounds as good (yes, it produces bigger and better sound than the SoundLink Mini, which performs remarkably well for its size).
The competition in the portable Bluetooth speaker arena is much stiffer these days and the Bose SoundLink Bluetooth Speaker III isn't as big of a standout as it was when the first version launched in 2011. It also isn't as feature-rich as some models. Still, its sound and battery life have improved (the battery life is a bigger jump than the sound), and its build quality remains top notch.
We could sit here and argue which competing models sound as good (or almost as good) for less money. However, at the end of the day, the Bose SoundLink Bluetooth Speaker III is a high-quality product that's an easy speaker to recommend if you can afford it. Audiophiles may not be wowed, but most people will be duly impressed by the quality of the sound it produces for its size.