Design and features:This Bluetooth wireless noise canceling home/studio-style over ear model provides good sound and excellent active noise reduction. Its closed design and electronic noise canceling feature reduce both outside noise and sound leaking out into your environment. The headphones work with or without the noise canceling feature being turned on. You can use the noise-canceling feature without listening to music, and the audio cable can be detached to get it out of the way when the headphones are being used for noise reduction only. The headphones have medium high sensitivity when powered with or without the noise cancelation feature turned on and when unpowered, so they can provide satisfying volume levels when used with home audio equipment and lower-powered portable audio devices. The HD 450BT has a volume control plus an integrated microphone and player function controls. Additional features include Detachable audio cable. Ear cups fold for ease of carrying and storage. Replaceable ear pads. Has volume, music player transport, call connect/disconnect, and noise cancelling control on the right ear cup. Has power on/off, Bluetooth pairing, battery level voice announcements. Supports Google Assistant, Apple Siri, and other undisclosed digital voice assistants when used with Bluetooth connected devices that have those features. The Sennheiser Smart Control app download for Apple and Android mobile devices shows the headphone battery level and can be used to adjust the equalizer and update the headphone's firmware. Bluetooth connected Apple mobile devices using iOS Version 5 and above will show the battery level. This model comes with Detachable 3.5mm audio cable, USB-A to USB-C charging cable, carrying bag. Free Sennheiser Smart Control app download for Apple and Android mobile devices.
Sound quality:We found the HD 450BT delivers sound quality that falls in the good range - it reproduces music and voice reasonably well despite the obvious shortcomings in its sound and excellent active noise reduction. With the noise cancelling mode engaged and the Sennheiser Smart Control app set at the Neutral Acoustical setting (as received state of the headphone) the bass (as in bass drums, bass guitars, stand-up bass, etc.) has good impact and goes deep, but is somewhat prominent and boomy. The midrange (voices, guitars, horns, etc.) is fairly even, somewhat hazy and dark (there is an opaqueness that covers up fine detail), and a bit soft and grainy. The treble (cymbals, the upper range of violins, etc.) is extended but a somewhat subdued and smeared (sounds that should have a delicate shimmer sound blurred). While the sound has a decent sense of liveliness, it is somewhat closed (sound-wise it's fairly obvious you have something plugging your ears) and does a so-so job of recovering room ambience. Warm character. The overall sound can be summarized as somewhat bassy and murky. When cord connected to AC powered devices this model may produce a more noticeable hissing and slight humming sound when it is powered on and the noise cancelling feature is engaged. Noise Canceling: Excellent noise reduction across the entire frequency range with the low frequencies reduced the most. Very faint hissing can be heard when there is no audio program to drown it out.
Comfort and Fit:We found that these headphones produce a sense of moderate pressure around the ears.
As typical of over-ear models the ear pads might feel hot and/or sticky after prolonged use.
Large
Users with larger ears might find that the over-the-ear fit of the ear pads feel cramped, or that the ear pads sit on, rather than around their ears; in that case the less-than-ideal fit around the ears might interfere with the ear pad seal and reduce the noise reduction capabilities of the headphone.
Users with larger heads might find that the headband does not have enough adjustment range to allow the ear cups rest properly on the ears and/or that the headband presses uncomfortably on the top of the head.
Stability
Some users heads may find that when they lean far forward the headphones feel a bit unstable and shift forward.
Other noise
When wearing this model while walking the muffled vibrations from each foot step can be heard through the headphones.
When the audio cord is used the sound of it rubbing on clothing may be heard through the headphones.
