After looking some reviews online it seems like this is a common issue that many people get which is highly unacceptable for releasing a defective product. They sound good though. I'm getting a replacement unit which hopefully fixes the problem, if not then I'm going to get a refund and probably buy a Logitech G533 or HyperX Cloud Flight.
UPDATE: The replacement still has the same buzzing in the left ear speaker. After testing out the Logitech G533 from a friend, they produced no buzzing so I'm going to get those instead.
The Corsair HS70 Wireless Gaming Headset provides exceptional comfort for hours of gameplay with its comfortable memory foam and adjustable earcups. Legendary CORSAIR build quality ensures long-term durability, and precision-tuned 50mm neodymium speaker drivers deliver superior sound quality. Low-latency, 2.4GHz wireless and a detachable unidirectional microphone provide crystal-clear communication, and with over 16hrs of battery life you won’t need to stop mid-game to recharge. Virtual 7.1 surround sound on PC immerses you in multi-channel positional audio, while plug-andplay compatibility with Sony PlayStation 4 brings wireless stereo audio to your living room.