I have searched a long time for a good, comfortable pair of Headphones. For some reason the top of my head is sensitive enough that I have never found a pair that were comfortable for more than an hour at a time. So I decided to modify a pair of good quality Headphones myself. I went through several iterations, each time increasing the size of the Headband to spread out the weight more. Then it occurred to me that someone had all ready created the perfect Headband to spread out the weight evenly, the Hat! So here is how I combined a pair of Headphones and a Hat.

I would like to point out that this involves modifying your Headphones, and will probably void any warranty you may have. It is also possible that you may damage your Headphones rendering them inoperable, I will try to warn you whenever any step could catastrophically damage your Headphones, but I take no responsibility if that happens. Do this at your own risk, you have been warned. Please read this instructable in its entirety before you decide to modify your Headphones, and proceed slowly and carefully.

Step 1: Choosing a Pair of Headphones

Here are the criteria for choosing which Headphones to use:

They will need to be Circumaural (over-ear) type Headphones, as in the picture above. These need to be comfortable Headphones after all.
The Headphones will need an Arching Support Frame above the Headband, as in the picture above.
The Headband will need to be easily removable.
If the Headphones you choose are single corded (the cord is only attached to one Ear-cup, not both), it is important that the Ear-cups are wired through the Arching Support Frames, and not the Headband. As we will be removing the Headband entirely. See note below.
The Ear-cups need to Swivel.
There needs to be a small lip between the Ear-cups and the Arching Support Frame, enough to catch a loop of string/Paracord in the following steps.

I chose the Audio Technica ATH-AD900x, and that is what you will see in the pictures of the finished product. Any of their Headphones with the Arching Support Frame and the Headband "Wings" will work just fine. The AD900x and any models like ADXXXXx are "open" style Headphones, meaning they will leak a lot of sound around you. If you want to use your Headphone Hat for gaming with voice chat, or on the go, I suggest using "closed" style Headphones instead. Audio Technica offers many similar "closed" style Headphones, look for models like AXXXXx. Here is a link to some models that will work, most of which are available on Amazon and elsewhere.

Note: If the Headphones you choose to use are wired through the Headband, it is still possible to use them here, but not recommended. Please see the note on step: Removing the Headband.

Step 2: Choosing a Hat

I chose to use a Corps style Hat. They feature two Riveted Holes on each side above the ear, which will allow for easy mounting of the Headphones. Any style Hat could work, you would have to figure out how to mount to the Hat (maybe adding Riveted Holes yourself).

I chose this Hat on Amazon, it is inexpensive, eco-conscious, organic, and comes in many colors. The Riveted Holes also happen to be perfectly seated above my ears (probably by design), allowing the Headphones to align properly. I can't guarantee they will work as well for other people, or that other Corps Hats will work at all, without modification of the Riveted Holes. I am not familiar with the design principles involved. However, I do have an "average" size and shape of head, so I imagine the Hat should work for most people, as long as it fits.

Step 3: Other Items Needed

Here are the rest of the tools and materials need for the Headphone Hat:

Two lengths of Paracord, each 1' - 2' long, of your choice of color, and the tools needed to cut and melt the ends. You could also use string or twine, as long as it is strong enough to support the Headphones.
Two pieces of a stiff thin material such as plastic, measuring 2" - 3" wide by 1/2" - 1" tall. I used a cracker box that I cut up and laminated 3 - 4 layers thick with Elmer's glue overnight. Each piece will need to be cut to size, and drilled with two 1/4" holes about 1" - 1 1/2" apart — the same distance as between the Riveted Holes in the Hat you purchased — as in the picture above. These will be referred to as "Rigid Supports" for the rest of the instructable.

Step 4: Removing the Headband

You will need to remove the Headband from whatever Headphones you decided to purchase, it is important to keep the Arching Support Frame intact and attached to the Ear-cups, as it is still needed to keep the Ear-cups aligned correctly, and pressed to your head.

In the case of most Audio Technica Headphones like the ones pictured, it is pretty easy. These Headphones use two Wings, one above each Ear-cup, in place of a Headband. Each Wing can be removed using the following procedure.

Start by removing the two screws on the inside of each Wing, as seen in the picture above (be sure to keep track of all parts and how they fit together).
The Plastic Plate holding the Ear-cup Swivel Joint in place can now be removed, be careful as the Ear-cup is still attached by a single small wire that can easily be ripped out.
Behind the Plastic Plate you will see another two screws holding the Wing in place, removing them will allow the Wing to be removed.
Put the Ear-cup Swivel Joint back in the groove under the Arching Support Frame, and place the Plastic Plate over the Ear-cup Swivel Joint.
Replace the two screws in the Plastic Plate.
Repeat for the second Wing.

For other styles of Headphones the procedure will certainly be different

Note: If the Headphones you choose to use are wired through the Headband, it is still possible to use them here, but not recommended. You will need to carefully remove the Headband while being sure to not damage any wire(s) connecting the Ear-cups. Then you will need to figure out how to use the Hat to keep the wire(s) protected, as it is pretty easy to accidentally rip the wire(s) out of one of the Ear-cups.

The first option is to route the wire(s) through the Riveted Holes in the Hat (see step: Choosing a Hat), but you may have to detach and reattach the wire (likely involving soldering, and beyond the scope of this instructable).
Option two is to route the wire(s) over or inside the Hat.

In either case you will then need to sew, or tape, the wire in place so it won't catch on anything when you put the Hat on, or take it off.

Step 5: Attaching the Headphones and Hat

The two pictures above show how the Paracord is used to attach one side of the Hat to an Ear-cup. The second image is a rough diagram of how I tied mine together. Here I will explain it in more detail, as there are some adjustments that need to be made to fit the Headphones to your head.

Attaching the Ear-cups:

Place the Headphones over the Hat, making sure the left and right Ear-cups match the correct side of the Hat.
Using one length of Paracord, start by tying a temporary Stopper Knot — a simple Overhand Knot works fine for now — near one end, leaving about 3" at the end for later adjustment.
Bring the working end of the cord between the Hat and the Ear-cup of your choice. The Stopper knot should be at the back of the Hat, matching the large red dot at position 1 in the diagram above.
Loop the working end around the top of the Ear-cup, catching on the lip of the Arching Support Frame (mentioned in step: Choosing a Pair of Headphones).
Place one Rigid Support inside the Hat, aligning the Holes in the Hat and Support.
Thread the working end through the front most Riveted Hole in the Hat and then the Rigid Support.
Thread the working end back through the rear most hole in the Rigid Support and then the rear Riveted Hole in the Hat.
Tie the working end around the Stopper Knot — using the knot of your choice, or see next step — leaving the Stopper Knot outside the loop as indicated by the green loop near position 1 in the diagram above.
You could stop here, but I chose to add another support between positions 1 and 2 on the diagram. I chose to use a Heaving Line Knot to both hold the Stopper Knot, and around the loop entering the front most Riveted Hole (diagram position 2).
Repeat for the second Ear-cup.

Adjusting the Ear-cups:

Put the Headphone Hat on your head, adjusting any rear strap if present..
Start on one side. Untie the temporary Stopper Knot from above (Attaching the Ear-cups: step 2), keeping a hold of the new working end.
Shorten, or lengthen, the loop holding the Ear-cup, by adding or removing slack from the working end, until the Ear-cup is comfortably aligned with your ear.
Take a hold of the working end where it exits the loop holding it in place, thus marking where to tie a new Stopper Knot.
Tie a new Stopper Knot in the working end, I recommend the Ashley Stopper Knot.
Repeat for the second Ear-cup.

Step 6: Finished Headphone Hat

And there is the finished product. Just a few last tips.

You may have seen my Mic in some of the pictures. If you want to use high quality Headphones while gaming, most don't come with an attached Mic, I recommend the Antlion Audio Mod Mic 5, it can be attached to most Headphones — all it requires is a flat 1/2" diameter circle to adhere to, even metal mesh works — and is an excellent Mic for gaming.

You may also have noticed white cotton balls inside the ear-pads of my Headphones, these can help to increase the pressure against your head, to increase the distance from your ears to the Headphone's drivers, and/or to change the angle at which the drivers face your ears (and thus change the sound slightly).