Sennheiser HD 650 vs Sennheiser GAME ONE PC Gaming Headset

The sound signature is near neutral but with a little emphasis on the lower frequencies. The bass is slightly forward with good punch and tightness. Explosions will have good rumble, without overpowering the other frequencies.
The mids are warm and clear, adding extra body to the sound. Game dialogue will be easy to hear.
Highs have good clarity, but are not forward in any way, so harshness is minimized.

The H650 is popular for its near neutral sound, which makes it quite versatile. The headphones can give a great casual listening, gaming, and movie watching experience yet are accurate enough for pro audio mixing. They are also lightweight and comfortable so you won't have any issues wearing them for hours.

Clamping force is not too tight. The ear pads and headband feature memory foam which are covered by velour material. The pads feel really soft on the head and allow airflow for minimized heat build-up/sweat.
The headband also features similar cushioning materials and minimizes pressure spots on the head.

The open ear cup design allows the sound to blend with your surroundings, giving it a natural width. It will also be easier to identify the direction of sounds, which can really help immersion.

The HD-650s do not feel heavy at all. They are usable for long music listening, movie or gaming sessions without feeling pain or strain on their head and neck.

While the cable connectors are proprietary, they can easily be removed from the ear cups with a firm pull. The popularity of these headphones means that there are a lot of aftermarket cables that can be bought.

You get a lot of quality for the price you pay. Sennheiser is by far the best.

The microphone ranks among the best and features excellent noise canceling which does a great job at eliminating background noises.

The open back design gives a feeling of width to the sound, which is great for movies and games. This effect is achieved without having to rely on virtual surround sound software techniques.

The GAME ONE has excellent sound quality and offers good balance between the different sound frequencies. The bass is tight and punchy instead of the overpowering and bloated low-end that most gaming headsets have.
Mids have good presence and fullness, so game dialogue should be easily heard. The highs are crisp and airy so a lot of detail can be enjoyed from games, yet the headset is not fatiguing to listen to, even with long gaming sessions.

Inside the ear pads, reasonably thick memory foam is used so they feel really soft. On the surface is high quality velour which not only feels really smooth but also allows for some airflow to the ears, minimizing heat build-up.