As a long time head-fi follower of modding headphones, like many people here, I've tried 2 of the most popular headphones mod: the grado cup mod (in aluminium) and fostex T50RP (aluminium cup mod with Audeze/Kennerton earpads)
Now it's time to try something new, to my knowledge, no one has tried customizing the HD800 before, so I've got to try it.
To start with, before starting the project, I've only auditioned the HD800 for 5 minutes, but based on the reviews the treble can be quite hot. My inspiration for this build is the sony R10, which some guy mentioned that has deeper soundstage than the hd800. So I knew a closed (or semi closed) headphones with great soundstage is possible.
Here is a sneak peek of the final (until now) prototype:
I bought a pair of replacement driver online and started to design the cups and baffle. The headband was taken from a superlus hd660. And eagerly I asked fellow head-fi member Rudy- Calico88 to CNC the cups from rosewood. Seeing his work on pictures, I had no doubt it would be good.
I know it is silly to make the first prototype of your headphones in very expensive material. The build quality of the cup from Rudy-from the tolerance, to the quality of the wood and the finish is top notch. I designed the baffle with lots of hole to tune the sound by covering them with tape.
The cup was then dampened with dynamat. Note that the in the middle of the cup there is a removable disc for open/close conversion.
First listen: It really showed me the potential of the driver. The hd800 is well built, it weight 35g compare to the plannar driver of fostex at 45g.
The treble detail is there, but with tuning, either I get a good soundstage but no bass or vice versa. Also the soundstage width is very good but not the depth. I spend 2 months playing with this and came to a conclusion: I made a mistake in the design: the cup's volume was too big, and even though the audeze pad is angled, the driver mounted flat on the baffle does not create a deep soundstage. Then came the difficult decision: I have to abandon the beautiful rosewood cup. At the same time, my Printrbot SImple Metal 3D printer arrived, I knew I have to change the design.
Still in love with the wood cup, I decided only to ditch the rosewood baffle for a new design, this time incorporated an angled driver relative to the baffle. The baffle protrude deep into the cup, therefore reduce the volume inside the cup. This new baffle is 3d printed from ABS. The baffle is left undamped ( not with dynamat or blu-tack)
Sound impression: The soundstage and bass is good, but there is a weird mid. I suspect there is a reflection on the ear side of the driver, due to a large volume created by this new baffle.
Now I have to decide to remove the driver from this beautiful cup to a fully 3d printed cup. On the new design, I also want to make the cup less deep. I made a mistake designing 2 huge drums stuck on my head.
WIth the inspiration come from the SOny R10 and the speaker B&W Nautilus, I want to design the cup without the concentric shape and inspired by a sea creature. Behold the sea shell cup.
The 3d printed cup was in grey, then bottle sprayed black.The design of the baffle also changed( it's the grey disc in the next picture). With new design, there is no reflection of sound on the ear side of driver.
I later spend 3 months listening and tweaking the sound, by opening/closing venting holes on the baffle and cup, damping the cup with blu-tack ( i will switch to dynamat later). After the dynamat, there is a layer of lambskin leather and cotton wool to further damp the driver.
THe jack is mini XLR from Rean.
Sound impression: (briefly compared to a hd800 in a showroom)
Now I'm totally satisfied with the sound. By mass damping the baffle and and cup, the sound is not bright. To my ear, the quality of the bass and mid is mostly the same as the stock hd800. However I am most proud about the soundstage. Although is closed ( or semi closed due to vents), the soundstage is not as wide but deeper than the hd800, as a result of extremely angled driver (angled ear pads + angled driver from baffle).
Now I know this is not the final prototype, because tuning headphones make you listen to them for a long time. As a result your ear becomes used to the sound. Therefore sometimes I have to go to the shops to compare to other headphones, and it takes time.
THe final pic is the headphones with different ditched component. Now I'm not throwing the rosewood cups away, still waiting for the next project.
Edit: new pictures of the build:
I made the cable from Double Helix Cable Nucleotide, Switchcraft 3.5mm jack (so I can use with my dx90 conveniently) and rean tiny XLR. For mini XLR, I think Rean is a good choice for it's aesthetic and affordability. The terminals are easy to solder. I use a plastic sleeving for speaker cable, similar to Techflex, but more coarse, you can see the braiding through the sleeves.
A clear shot oy the yokes assembly. The stock yoke from the Superlux HD660 is too small (the same size as Beyerdynamics), so I made a new yoke from stainless steel.I cut the shape from 2mm steel plate, then grinded and polished by dremel.
The hinge of the yoke (small rectangular plastic thing) is 3d printed from carbon fiber abs, glued on to the yoke. Then I use M3 socket head screw to attach the yoke to the cup.
There are 3 holes near the mini xlr connector. I designed the cups with vents at the front, but I need to drill extra 3 holes for tunning.
I used similar method to the Denon Markl mod, adding foam to the thicker side of the pads and cotton to the thinner side. It just sound good to my ears in this config. Also note the 2 holes I punched out of the earpads, helps thinning the mid.
The naked shot: the baffle is 3d printed from 3 parts, saving me from printing in 1 go and spend days removing the supporting materials. THe white blutack is there to mass damp the baffle and reduce reflection from the driver. There are small vents connecting to the main cup chamber. this reduces the pressure and again helping the soundstage, but too many open vents and the sound becomes thin with peaky treble.
There is also a lip for mounting the Audeze earpads.
Final pics showing the beautifull hd800 driver and my crappy craftsmanship with lots of blu-tack
Edited by frank2908 - 2/6/15 at 11:40pm