Sennheiser HD 4.50BTNC Bluetooth Wireless Headphone
The lower outside panel of the right earcup houses a micro USB connection for the included charging cable, as well as a connection for the included 3.5mm audio cable. The cable lacks an inline remote, which is a bit of a bummer, but it does twist and lock into place so it won't fall out, which is a nice design choice.
Next to these connections, there are controls for power/pairing, a multifunction button that controls playback, call management, and track navigation, and a volume rocker button that works in conjunction with your device's master volume levels. The volume button, when pressed on both sides, let you activate or deactivate the active noise cancellation circuitry.
In addition to the charging and audio cables, the headphones ship with a black protective zip-up pouch. You can keep the headphones powered up in order to use the noise cancellation circuitry while using the audio cable.
The built-in mic offers excellent intelligibility. Using the Voice Memos app on an iPhone 6s, every word was crystal clear—there's a lack of bass response in the mic, so things sound slightly thin, but there are few additional audio artifacts, which is rarely the case with built-in mics on Bluetooth headphones.
Sennheiser estimates battery life to be roughly 19 hours, or 25 hours with noise cancelation switched off, but your results will vary with your volume levels and your usage of the various features together or on their own. The headphones works with NFC-compatible devices, but pairing via Bluetooth is also a simple and quick process.
Sennheiser's NoiseGard noise cancellation circuitry is quite effective. It doesn't match the noise-canceling prowess of the QuietComfort models from Bose, but these headphones are also far less expensive. Like most inexpensive noise cancellation circuitry, it produces a very subtle but audible hiss. That said, the hiss is far less audible than it often is, and it's not unpleasant in the slightest—think of it as exceptionally faint tape hiss—and it's unnoticeable when music is playing at even low levels. The noise cancellation effectively tamped down powerful whirring AC noise, and will be effective on planes and trains. Voices and office chatter are not as easily canceled out, but for $200, there are few models, wireless or not, that offer noise cancellation this effective.
On tracks with intense sub-bass content, like The Knife's "Silent Shout," the headphones deliver a strong low frequency response that will appeal to bass lovers. They don't get quite as loud as most competing models, but this isn't bad news—the maximum volume when paired with an iPhone 6s was still very high, and the bass response on this track was clean and full at both high and moderate listening levels.
Bill Callahan's "Drover," a track with little in the way of deep bass, gives us a better sense of the overall sound signature. The drums on this track sound powerful and thunderous through the HD 4.50 BTNC—it's not so overdone that things feel unnatural, but there's no denying this is a bass-forward sound signature. Callahan's baritone vocals also get an extra helping of low and low-mid richness, but the high-mids and highs are thankfully boosted and sculpted as well. Thus, the vocals get plenty of definition and treble edge, and the guitar strumming and high-pitched percussive attacks are bright and clear.
Unfortunately, on this track in particular, we notice that the noise cancellation has an impact on audio performance. It's subtle, but this is something that shouldn't happen, no matter the price. While the noise cancellation doesn't make the audio sound bad, there's a clear difference in the treble response—with the cancellation on, you hear a little bit less high-end. There's also a slight shift in bass response—with cancellation activated, there's more sub-bass.
We've noticed this occurring more and more lately—the headphones come to mind. Perhaps it's something to do with combining noise cancellation with Bluetooth capabilities. Regardless, it's a side effect that used to be the sole domain of cheap, poorly designed noise-canceling headphones, and now we are seeing it in higher-priced, otherwise well-designed pairs. The main difference is that, unlike with more inexpensive offerings, neither mode here sounds bad, but it is worth noting that the two modes sound markedly different.
On Jay-Z and Kanye West's "No Church in the Wild," the highs are dialed up—the vinyl crackle typically relegated to the background is pushed forward in the mix, and the kick drum loop's attack gets plenty of high-mid presence, making it particularly sharp. The sub-bass synth hits that punctuate the beat are delivered with serious force—it sounds like there's a subwoofer hidden somewhere in the earcups.
Orchestral tracks, like the opening scene in John Adams' The Gospel According to the Other Mary, receive more bass boosting than purists will like, but the overall effect is at least balanced—the boosted highs are also prevalent, so while the lower register instrumentation is pushed forward in the mix, the higher register brass, strings, and vocals are still bright and in command of the spotlight.