Build a Hi-Fi Headphone From Scratch

I build this "golden plated" headphone from scratch with a pair of 40mm dynamic drivers. My goal was, as I named it a Hi-Fi headphone, it must beat or at least on par with my $100 Grado MS1. So I deliberately pick this close-end (mainly to control the distortion caused by over driving in low frequency) metal shell and Hi-End drivers. So this is what I finally made - it's 32ohm and high sensitive (110dB+) and can easily driven by iPhone.

As judging the sound quality could be very subjective and, to be very honest, full of bias. I plan to do to at least partly address this trustworthy issue is to objectively measure and publish the performance. Professional acoustic measurement instruments could hundreds time expensive than an earphone, I'm trying to figure out a way to lower the bar to <$200 with reasonable precision...

Also see my other Instructables

1. Build an in-ear earphone as the size smaller which make it easier to build a FR measurement instrument.
2. Black Walnut Wooden Shell Headphone with 40/50mm Sennheiser Drivers
3. Build a Headphone with Beats Studio 2.0 drivers

So here is all the components:

1. A headphone shell - overhead bracket with internal wires and 3.5mm socket, and housing for the driver units
2. Up/under protective covers for driver units
3. 2*40mm dynamic drivers, 20-20KHz FR, 32ohm, hi-resolution
4. 1*OFC cable with 2*3.5mm male plugs

The tools are what you can buy from most e-stores or BestBuy

1. Soldering iron. 20~30W preferred. DON'T use >60W or overheat to 300 degree C
2. Glue. E8000 is the best of the best, or you can use any healthy/harmless glues for metal and plastic. Don't use 502 or any other instinct dry glue!
3. screw drivers, knife...

this is to glue the dynamic driver with the upper cover. Notice the position of the soldering panel, make sure you point it to the right direction to ease soldering in the next step. it takes ~30min before E8000 being reasonably dry and strong for the next step.

Also notice when gluing, absolutely NO glue can be left on either the diaphragm (front) side or the backend side (block the holes). Proceed with caution!

this is to connect (soldering) the cable with the driver units. Notice the mapping cannot be wrong as the driver is with polarity. Wrong (reversed) wiring makes the driver working in wrong condition (although it still produce sound).

Make the soldering duration as short (<2S) as possible as the soldering panel is very fragile!

Then screw the upper cover, driver unit, and the undercover together to the housing... you almost done!

you shall get a "working" headphone by now, put on the ear pad, plug it to you cell phone and you can start enjoying it, cheers! You'd better have another headphone as a reference to verify if it works properly.

However, if you are really picky and want to fine tune the "flavor" of the sound, here are some tips.

1. if you are a bass-head and really want supper bass hitting your ear canal, you can try to open up some covered holes on the backend of the driver (you can see these holes from the front end). Or you can drill small holes on the housing to make it a half-open end.
2. Try different dynamic drivers. they offer so different sounds. Grado MS1 is very good at mid-band and offers very bright human voice. the one I used in this project performing as least as good as MS1 on human voice, but well beat it by driving much deep in low-band.

Hope you enjoy it... Please leave your comments or message me, I'd be glad to share what I learnt.