World's Largest Dynamic Driver Headphones (DIY)
Today we are looking at something a bit different. As far as I can tell I've created a pair of world record wireless open back headphones by accident, and it didn't cost me much to do.
The build processes.
I was attempting a speed mod on an old tape player from a boombox with a friend and at the end we were left with a pile of random parts and 2 100mm dynamic speaker drivers.
At first before committing and spending lots of time I made a basic mock up to see what they would sound like. To my surprise they sounded extremely good and had incredible wide soundstage.
I then spend a day flattering and trimming the front grill of the boom box so I could use it to protect the driver from being touched.
After this by using some wire form an old cooker grill, furniture foam and scraps of wood I made the headband.
The cups are attached on using nut and bolts I brought attached to small, wooden blocks, so the cups can be swivelled. By angling the foam ear cups I could get much better imaging. I used cocktail stick grill to protect the drivers from the outside and 2 sliding metal pipes of similar diameter between the cups and the headband so it can be adjusted to fit on any head size. A small piece of elastic ribbon is used to give the sliding mechanism resistance, so it stays where you leave it.
The original headphone jack from the boombox is wired up to the drivers with telephone cable which means the headphones can be used with any 3.5 mm headphone jack.
To make the headphone wireless I used a Fiio BTR3K which supports lossless codecs, Bluetooth multipoint and Bluetooth 5.0.
How do they sound?
The best thing about these headphones is their enormous sound stage and how clear they sound. They make my Sennheiser HD 599s sound closed in and muffled in comparison. These headphones sound much more like my friends AKG 701 in terms of soundstage, maybe even bigger. At the same time, they are very detailed and clear like my Galaxy Buds Pro, much more so than the Sennheiser's.
I have no way of measuring frequency response but sound pretty flat apart from a bump in mid bass which doesn't result in them sounding muddy at all but gives them some tasteful thump. They do Lack some really low subbase but using the EQ built into the Fiio you can get them to sound pretty flat. By putting tape around the edge of the foam cups you can get back some of the deep subbase at the cost of how open they sound.
These may be the most unique and open, open back headphones I have ever seen; the ear cup is literally made out of the driver case and the driver is 100 mm in size which as far as I can tell is world record for dynamic headphone driver (if I'm wrong please email me). overall, I'm extremely happy with the outcome and they will live hanged up by my desk.
Video/pictures.
