Overall, the headphones are accurate, deliver good, well-defined bass, and are fairly open-sounding for a closed-back headphone. I should make it clear that this isn't a bass-heavy headphone, and those who crave more bass will most likely be disappointed.
A Bose rep told me the sound quality should be the same as that of the previous model, but we did notice some small differences, which may be attributable to the new design of the headphone, not the driver. Even tiny design changes can affect the sound.
I found the bass a little tighter on the Around-Ear II and my colleague Justin Yu agreed, though he thought the old model sounded slightly more open. I preferred the sound of the new model -- I like my bass a little tighter, but that's a subjective opinion and others might prefer the old model.
Our gripe with Bose's earlier around-ear models was that the treble was a tad brash, overemphasizing instruments such as cymbals -- it's a matter of taste whether you like that "extra sizzle" or not. With each new iteration, the treble seems to be get a touch smoother and I didn't have a problem with it in this model.
In a lot of ways, that smoothness has become Bose's sound signature for its headphones, which are designed to versatile and work well with all types of music. They're also designed to make every thrown at them -- even poorly recorded and compressed tracks -- sound decent.
What's missing is a little of the richness, excitement, and clarity that you may get from a higher end headphone. You get more of that with a headphones like Sony's MDR-1A or Sennheiser's Momentum 2.0, but those cost headphones cost significantly more. Meanwhile, a headphone like Audio-Technica's ATH-MSR7 offers better clarity and a little more openness, but it's not as comfortable as this Bose and its abundance of clarity reveals harshness or distortion in recordings.
Smooth sound meets superior comfort
Bose's non-noise-canceling around-ear headphones have always been a more affordable alternative to its QuietComfort line, which starts at $300. With the SoundTrue Around-Ear II, Bose has made some small but important design changes that make the headphone more durable and arguably sound a touch better. It's not cheap at $180, but it is a very likable, ultracomfortable over-ear headphone that you can wear for long stretches without a problem.