[frank2908]

My latest version, V4
I completed this last year actually but never posted since I traveled round the world for 1 year, so left this baby at home and just picked them up last month. I have a new design but my 3d printer broke and I'm on the road again,anw these sounds great with Chord Mojo

It's the first time I switch to open ear design, and there is a removable magnetic cap to convert to closed (not shown in photo). There is a dust screen cut off from stax sr007 earpads fabric. The driver cover is printed with honeycomb pattern

On the baffle and earpads rings there are magnets so I cant swap pads easily. Now I have the diy Stax pads (Sr007 with memory foam fill ) and Shure Alcantara earpads. The Stax produces a better soundstage and a bit more comfy because the memory foam I used is very soft, but if I'm not in a room with AC, then I switch to Alcantara pads. The alcantara has a bit smaller soundstage but better bass (tiny bit)

The baffle is left open and sealed with 3M Micropore tape, which has the best balance between sealing (more base) and open (soundstage) IMO.
The original idea of making the headphones with huge closed cup like R10 and HD800 driver failed, not because of the cup but because the volume between the driver and the ear was not big enough, and the hd800 are designed for this huge volume. Now I plan for next build to be convertible between open/closed and over ear/ on ear. When you have an expensive headphones and a Chord MOjo, why do you have to buy another portable headphones? I believe to make a convertible portable hd800 would sound at least better than any $500 portable headphones anyway

 

[RenZixx]

My latest version, V4
I completed this last year actually but never posted since I traveled round the world for 1 year, so left this baby at home and just picked them up last month. I have a new design but my 3d printer broke and I'm on the road again,anw these sounds great with Chord Mojo

It's the first time I switch to open ear design, and there is a removable magnetic cap to convert to closed (not shown in photo). There is a dust screen cut off from stax sr007 earpads fabric. The driver cover is printed with honeycomb pattern

On the baffle and earpads rings there are magnets so I cant swap pads easily. Now I have the diy Stax pads (Sr007 with memory foam fill ) and Shure Alcantara earpads. The Stax produces a better soundstage and a bit more comfy because the memory foam I used is very soft, but if I'm not in a room with AC, then I switch to Alcantara pads. The alcantara has a bit smaller soundstage but better bass (tiny bit)

The baffle is left open and sealed with 3M Micropore tape, which has the best balance between sealing (more base) and open (soundstage) IMO.
The original idea of making the headphones with huge closed cup like R10 and HD800 driver failed, not because of the cup but because the volume between the driver and the ear was not big enough, and the hd800 are designed for this huge volume. Now I plan for next build to be convertible between open/closed and over ear/ on ear. When you have an expensive headphones and a Chord MOjo, why do you have to buy another portable headphones? I believe to make a convertible portable hd800 would sound at least better than any $500 portable headphones anyway

Man those look vintage, like Frankenstein made headphones. Have you tried different damping materials?

 

[frank2908]

I tried mostly before damping material at the back of the driver, havent tried much between driver and ear.
I like micropore, if only they are black, would look nicer. Maybe I should use a black marker pen and make them black.
This is the lightest headphones I made so far, around 300 gr.
I'm looking for a protective mesh on the driver side of the driver, something that would be acoustically transparent and block out all the dust. The aluminium mesh on the original HD800 is too coarse, as I might bring them out side of the house its not gonna stop dust getting in there.
Ideally the mesh covering the inside of the hd800 is great but I can't find something similar.Anyone have any idea?

 

[RenZixx]

I tried mostly before damping material at the back of the driver, havent tried much between driver and ear.
I like micropore, if only they are black, would look nicer. Maybe I should use a black marker pen and make them black.
This is the lightest headphones I made so far, around 300 gr.
I'm looking for a protective mesh on the driver side of the driver, something that would be acoustically transparent and block out all the dust. The aluminium mesh on the original HD800 is too coarse, as I might bring them out side of the house its not gonna stop dust getting in there.
Ideally the mesh covering the inside of the hd800 is great but I can't find something similar.Anyone have any idea?

Have you tried natural felt? They seem to have amazing effects, try em!

 

[frank2908]

DIY bug got to me again, then I dropped the v4 and broke the single arm yoke ( pla is too brittle) so I make new version with the yoke connected on both side.
V5

The connector is switched from the heavy and bulky mini xlr to 3.5mm

The open surface on the baffe is covered with micropore and lined with liner material
Driver is angled at 10 degree.

I did not try the resonator mod yet, maybe next time.
The driver is attached by screw to the frame and yoke, the baffle and earpads are completely modular, attached by guiding screw and magnet, this way I can try different baffle design without making them all from scratch.

Another new improvement is the sliding rods are switched from 5mm aluminium to 3mm carbon fiber to reduce weight, the carbon fiber rods are more flexible, bending a bit to increase comfort. And I added mechanism to adjust the angle of the yoke, therefore I can adjust the clamping force by turning the screw.

Now to the sound:
First I left some plastic area of the baffle not covered in micropore, there was lots of reverb and reflection in the mid, completely cover all area reduce this, and adding the liner further reduce this effect. The soundstage is wide, imaging is good, but the singer voice appear to be not too much in front of my head, which Im not sure if the hd800 is supposed to do the same?
There is some small air gap between the baffle and the frame, therefore there is some bass leak. I will try to seal them with blutack or put some foam in between to seal them.
For the last 2 builds, the design is turning towards the open and large baffle volume of hd800 a bit. But last night I downloaded the manual for the sony r10 and has some design inspiration from them. Actually I tried the idea once but did not have enough material to play with.

 

[frank2908]

New version is very light, without cable 293 g, with connector is 306g

 

[RenZixx]

Well try adding some dynamat. Every time I see those headphones I think of Frankenstein on steroids (which is really good).

 

[frank2908]

I'm trying to make them lightweight to increase comfort. Also I dont have access to dynamat atm. But making them lightweight and regid would reduce energy stored, therefore less vibration. The question is: is this regid enough.
The debate is similar to the turntable world, rega vs heavy turntable vs suspended turntable.
The sony r10 cup and driver and baffle is connected almost in 1 piece, then suspended from the frame, earpads by 3 screw and rubber damper, this is something I would like to try next

 

[RenZixx]

Dynamat = less vibration.
I would suggest CNC carbon fibre, its rigid AF and light as ever. So use a slightly thicker carbon layer and small pieces of dynamat.

 

[Maxx134]

Dynamat = less vibration

There are two areas I pinpointed that are a concern for the driver vibration onto the frame.
I have addressed this in my mod thread (linked in my sig)
It not only on both sides, but on the plane of angle of the frame that it extends outward to.
This all but eliminated the 6k ringing and then also the diffused pattern nature of the metal basket, which I see here has been replaced...
Regardless damping will benifit here but the downside is the nature of the dynamat material (messy if reversing)
Dynamat extreme is the only one I can recommend due to it having the most effect of these type materials..

 

[RenZixx]

There are two areas I pinpointed that are a concern for the driver vibration onto the frame.
I have addressed this in my mod thread (linked in my sig)
It not only on both sides, but on the plane of angle of the frame that it extends outward to.
This all but eliminated the 6k ringing and then also the diffused pattern nature of the metal basket, which I see here has been replaced...
Regardless damping will benifit here but the downside is the nature of the dynamat material (messy if reversing)
Dynamat extreme is the only one I can recommend due to it having the most effect of these type materials..

Agreed! Dynamat extreme is the best, sorbothane is also another option. I would combine the two for the best effect.

 

[RenZixx]

Also another thing is that you can put dynamat on the headband (make sure its hidden) this should eliminate most of the ringing and transfer most of that energy into actual sound or bass rather then vibrating the headband. Mostly on the yokes tho.

 

[frank2908]

Another way to reduce vibration is to reduce the surface contact area between parts, similar to the pointy legs of speakers and turntables or damp them using rubber.
I have been studying the Sony r10 manual and design and they incorporate this idea. It can be divided into 2 main units:
Wood cup, driver and wood baffle (where the driver is angled and has lots of holes on them) I believe those holes dont "breathe". They seems to be covered by paper tape with minimal breathablity, and they are there to reduce weight imo
Frame, earpads and the yoke of the headband. This is oppose to most other headphones where the headband is linked to the cup or baffle, hence can transmit vibration from the driver or from the headband.
This 2 main units are joined by 3 screws and rubber ring, therefore isolate unwanted vibration. The wood part seems to be let vibrated according to their design, and the frame, earpads are isolated.

 

[Maxx134]

Agreed! Dynamat extreme is the best, sorbothane is also another option. I would combine the two for the best effect.

In my testing, sorbothane worked best in either a slightly pressurized or slightly tensioned position.
I have used it more successfully in the tensioned position of (around) a driver motor assembly, but the HD800 driver is a different animal completely and it is my opinion that the designers were very radical in their approach.

 

[Maxx134]

Another way to reduce vibration is to reduce the surface contact area between parts, similar to the pointy legs of speakers and turntables or damp them using rubber.
I have been studying the Sony r10 manual and design and they incorporate this idea. It can be divided into 2 main units:
Wood cup, driver and wood baffle (where the driver is angled and has lots of holes on them) I believe those holes dont "breathe". They seems to be covered by paper tape with minimal breathablity, and they are there to reduce weight imo
Frame, earpads and the yoke of the headband. This is oppose to most other headphones where the headband is linked to the cup or baffle, hence can transmit vibration from the driver or from the headband.
This 2 main units are joined by 3 screws and rubber ring, therefore isolate unwanted vibration. The wood part seems to be let vibrated according to their design, and the frame, earpads are isolated.

This is very good to analyze the rear of the headphone designs.

In my analyzing the 800,
the main issue I see wasn't the rear, but instead was that the driver was designed with intentions to propagate the soundfield outward from a distance, thus the "cage" it has.

Any internal damping to the. Front "cage" & baffle area tends to effectively reduce the precious soundstage it was designed and famous for having.

I also seen this similar approach in the Abyss phi.
I personally still think the Phi is larger in soundstage, but thats another topic.

So, Allowing sound wave to disperse naturally outward, (like a speaker does in a room) actually helps in creating large soundstage.