The oval ear cups have an ergonomic shape, but there isn’t much room for average to above-average ears to fit comfortably. Some users have even reported that these headphones fit more like on-ears than over-ears. While that’s annoying, it does make the headset more wearable than the expensive Bose Noise Cancelling Headphones 700. However, the ear pads can always be replaced, which is good news for hobbyists and anyone looking to upgrade from leatherette. We enabled Bluetooth and noise cancellation and exposed the headset to a constant volume of 75 dB(SPL), and the battery lasted 27 hours and 2 minutes. That’s a bit less than the claimed battery life of 30 hours, but still exceptional and more than necessary for a typical handset. When the battery runs out, it’s easy to recharge via the included USB-C cable. There is no quick charge feature, so you’ll need to allow two hours to fully charge the headphones. The Sennheiser HD 450BT is a mid-range headset with active noise cancellation that reproduces low-frequency sounds half as loud when ANC is enabled than when it is disabled. This change is audible, but you can definitely get better performance with other headsets that cost just a bit more, like the Sennheiser PXC 550-II. When using the headset outdoors, wind and noise from passing cars were less pronounced, but both sounds remained clearly audible. Passive isolation does a lot of the work when it comes to blocking out the mid and high frequencies. That’s because it’s very difficult for ANC to suppress unpredictable sounds like speech and the usual clang and clang, which are often above 1 kHz. To get the most out of noise cancellation, make sure the headphones fit well and there are no gaps between your head and the ear pads. Sound quality is Sennheiser’s forte, whether they’re over-ear headphones or true wireless earbuds. You can always count on Sennheiser to make at least one product that sounds good in all genres of music. Sennheiser stays true to its roots, with a few minor deviations that make for an appealing but enjoyable sound. The slight boost from 20-100 Hz makes the bass a touch louder than the mids, but not so loud that it’s hard to make out voices. Another emphasized range is between 450Hz and 3kHz, where the main instrumental tones can be heard.
