DIY headphone update
Sep 20, 2002 at 12:05 PM Thread Starter Post #1 of 41

setmenu

Strongly opposes a DBT-free chair forum.
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The MK2 parts arrived the other Day.
The Diaphragms before the frame parts, so I lashed together
a pair of phones with tape to hear what those new diaphragms
sounded like.[I just could not wait untill the frame parts arived..
patience patience..]
The carbon framed transducer is the first sample batch of parts
for my approval so I am still awaiting its companion then I will
make up the MK2s proper.
The visible diaphragm is a reject[a few incomplete traces]
so I installed it as a test.

The lash up phones rattle like hell with heavy bass [These things
are really bodged together] but sound great.
They compare well to the staxes for clarity and are lovely on
vocals.[they do not have that treble lift of the staxes]
The bass has more extension than the MK1s though the rattles
and dodgy build preclude any real assessment there.
The over punchy mid bass has gone.
I know it is not really fair to make any assessment on the mk2 sound based on the lash ups but I am happy thus far.

I am encouraged enough now to go a head and produce a mk2B
design for easier diaphragm installation,and maybe produce an
entirely different version using the same diaphragm but different
magnetic circuit[more akin to a planar speaker than a ribbon]for comparison and to see what extra bass extension can be achieved with this diaphragm.


Setmenu
 
Sep 20, 2002 at 2:16 PM Post #3 of 41
Ooooh!! Flat pads!!!
wink.gif


Setmenu

This thread will be an interesting one to follow as you progress. Please continue to post progress pictures.
 
Sep 20, 2002 at 4:02 PM Post #4 of 41
Way too cool, setmenu. I'm going to be watching this thread.

So how much of this do you actually do yourself? I don't really know much about how the electical signal is converted to mechanical energy, but how do you get the diaphram to vibrate correctly? What's your diaphram made out of? How are you going to tweak the sound on these things?

kerelybonto
 
Sep 20, 2002 at 10:40 PM Post #5 of 41
Good to see the design is progressing, setmenu. That is really starting to look like a set of respectable drivers now. You may need to fill in all the details of magnet material etc. to keep us happy! Maybe some exploded diagrams etc. I have no exsperience with the carbon fiber and would love to hear about the ins and outs of working with it. (All of course if you can find the time!) Thanks for sharing with us.
 
Sep 21, 2002 at 11:42 AM Post #6 of 41
Thanks for the interest people.
JMT
Hehe..I am hoping to keep the profile of these as flat as possible.
Kerelybonto
I have designed 100% of these.
Unlike the Mk1 transducers in which all the parts were handmade
the MK2s were CAD designed and the various parts produced
by specialist company's from the relevant drawings.
Mail order custom parts is a real joy
biggrin.gif
.
The reason for this is one of time and consistency.
Also to change parts is simply a matter of altering a drawing...
very handy.
As I require numerous pairs or phones to compare design changes , this seemed the logical way to go.
I can now order kits of parts to assemble rather than go through
the process of making endless Identical parts.[yipee!].
I suppose the downside is cost,but in real terms that is cheaper
than spending valuable hours making parts.

The principle these phones work on is the same as a ribbon speaker.
The diaphragm which is copper clad polymide film with an etched
field coil sits in a magnetic field which runs between the flat pole pieces.
It is really no-different to a conventional moving coil design except
flattened with the coil itself acting as the cone so to speak.
It is a vastly lass efficient design at converting electricity into
sound compared to a conventional design but has several advantages over a coned design by having the diaphragm
driven over the whole surface.
Similar to those of an electrostatic transducer.
regarding tweaking the design there are numerous methods.
the Picture shows the transducer 'naked' without any dampers
fitted.
These dampers are made from porous materials and are used to
tune the bass resonances etc by way of a resistive load on the diaphragm.
The diaphragm itself is sensitive to how it is 'folded' and how the captive ends are terminated[not to mention the compliance of the
material and coil itself].

Budgie
The magnets are Iron Boron Neodymium,very powerfull.
Infact I wish this design was more efficient and less magnet hungary because there is a fair amount of leakage.
whilst the carbon parts here were done by someone else I have
made many things from the stuff.
It is easy to cut and machine but blunts tools quickly so tungsten
tools help there.
My maine complaint about the stuff is the dust...evil black dust.

Nobody thinks the pictured phones are the height of audiophile
Styling then?
frown.gif
wink.gif



Setmenu

Team Planar
 
Sep 21, 2002 at 6:49 PM Post #7 of 41
They're attractive in their own unattractive way, setmenu.
wink.gif


Thanks for the additional info. It's pretty amazing, really -- I didn't think anything like this could be done without a major investment in equipment.

I'll keep watching. Let us know how it's going.

kerelybonto
 
Sep 25, 2002 at 3:58 AM Post #8 of 41
you are my hero.
 
Sep 25, 2002 at 10:24 AM Post #9 of 41
Thanks people,I will post more as and when the next stage
comes together.

Setmenu
 
Oct 11, 2002 at 7:53 PM Post #10 of 41
redface.gif
redface.gif
Been reading my past threads on this project today.
Interesting how things have come on...waxed somewhat too
lyrical about their sound at times
redface.gif
but hell thats what naive
enthusiasm does for you
tongue.gif
.

With all the parts at my fingertips to assemble the MK2 phones
I am just summoning up the courage to install the diaphragms!
I have made this aspect of assembly rather difficult for myself
in this version..ho hum.
To test various diaphragm pleats etc I will have to modify the
design to ease assembly..Mk2Bs =yet more ££.

On the subject of diaphragms I have discovered a source of
even thinner laminates, giving me the opportunity to reduce
the weight by as much as 50% ..yum
biggrin.gif
.
I have resisted following up though[as yet
eek.gif
] due to costs.


Thanks to everyone who has shown an interest in my project
biggrin.gif

as I realize it is hardly mainstream on the DIY front, friends and
family think I am completely mad.....maybe they have a point
very_evil_smiley.gif
redface.gif
tongue.gif
.


Cheers

Setmenu
smily_headphones1.gif
 
Oct 12, 2002 at 4:19 PM Post #11 of 41
Setmenu
Wow, ribbon headphones. For better or worse, you are a pioneer.
smily_headphones1.gif


I keep telling Nick he needs to build some horn headphones with the same design sensibilities as the K1000. Then he could win the most eccentric Head-Fi'er award.
 
Oct 13, 2002 at 6:23 PM Post #13 of 41
Cheers Folks.
Those gaffer tape phones are doubly ugly since I chopped the
ear-pads around whilst experimenting with them..hehe.

Once the carbon shelled pair are up and running they will look
a lot nicer[and sound so too] but the ear-pads will remain
hand cut foam until optimized.
The ear pad side of things is a bit of a project in it's own right.
The headband will be from a pair of Peltor ear defenders....
clean functional and workmanlike but comfy.

The long term aim[dream/fantasy] in the aesthetic sense is to go for installing
the transducer parts into a wooden frame/enclosure with a
suitably stylish headband.

But OH the cost and time of this sort of project
eek.gif

Fun though it is ,too much time has been stolen in the last
couple of months!

Once I finally get this pair together and sorted I will have to do
a couple of pairs of the MK2Bs just to test out some other
diaphragm configuration etc.

After that it will be my next stop and assess point.
That will be the point I will go and get some brutal third party
view points on them.
Climb out of the goldfish bowl so to speak.


Setmenu
 
Oct 20, 2002 at 2:40 AM Post #14 of 41
Just been listening to the next gen phones....
Nice!..good improvement over the MK1s[and tape lash up version
redface.gif
].
Whilst as I suspected this particular design would be a complete
beestard to assemble, and was , it still sounds nice even with an
over tight ribbon tension, meaning that the particular resonance I hate,to some extent still remains[unlike those nasty lash tape phones shown which in all their crudeness are so slack as to not resonate in that
area..DAM!].

Still Mk2Bs on their way!!

And anyway..whooo hooo..Pleased..Mostley
biggrin.gif




Setmenu
smily_headphones1.gif
 
Oct 21, 2002 at 1:15 PM Post #15 of 41
This a picture of the MK2s [At last!].
Ear pads are still the standard foam and tape approach but
that does not matter for now.

As I mentioned in a previous post,the ribbon tension is a little high
in this model due to the difficulty in controlling the tension during
installation,but this awkward assembly procedure will be fixed
in the next model.
This will allow for far easier testing of different diaphragms.

Sound wise [even allowing for some sonic effect due to the previous mentioned ribbon tension] things have improved leaps
and bounds over the first model.

It's a hugely powerful sound with a wide bandwidth that goes far
lower than the previous model[could hear a 'note' at 10hz on a
test cd..whatever that actually means
rolleyes.gif
]
Infact the power at very low frequency's is the most odd thing I have experienced with headphones,more akin to listening to
speakers
confused.gif
very unsettling.
Those lows seem controlled too if a little[lot compared to Staxs]
overblown on some recordings.

The rest of the Spectra seem sweet as well.

I cant wait to get the next version sorted because ridding them of
that tight ribbon will definitely clean up the sound further[as can be heard on the Tape lash ups].


Setmenu
smily_headphones1.gif
 

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