The Bose QuietComfort 25 were released in 2015 and you can still buy them today. They are kind of like a wired version of the Bose QuietComfort 35. They have a slightly dated look, and boast almost as good levels of active noise-cancellation and sound quality as Bose’s QuietComfort 35. The important thing to remember is that even though these are wired headphones, they still need to be charged so you can turn on the active noise cancellation. Otherwise, they just work as normal over-ear headphones.
In early powered radios, the headphone was part of the vacuum tube's plate circuit and carried dangerous voltages. It was normally connected directly to the positive high voltage battery terminal, and the other battery terminal was securely grounded. The use of bare electrical connections meant that users could be shocked if they touched the bare headphone connections while adjusting an uncomfortable headset.
I’m a former Mixer and DJ and I’d highly recommend the Beyer T1 for mixing. It is not absolutely flat, but it is an all around proper Audio Technicians Headphone. For flat response, I might eyeball the HD800 but the low end might not be the best if you are often mixing tracks with solid low ends. Flat might not always be the best option ( my opinion ). If you need to mix heavy bass tracks, it is better to have a headphone that responds better to low end EQ and is generally accepted as a more well rounded headphone.
In-ear headphones are like earbuds but are an upgrade to them. These headphones fit into the wearer's ear canal and stay in place with the use of foam or rubber tips. These tips are available in custom sizes so they can fit each individual wearer. When a proper fit's achieved, in-ear headphones reduce outside noise and deliver sound quality at about the same level as over-ear and on-ear headphones.