[szerecsen]

  So here's something you don't see every day.
The guts of a PMB 8.
No headphones were harmed in the making of these photos 

 
  
 
  
 
  
 
  
 
I was able to successfully open both cups without making any (major) damage (a few tiny scratches).
I replaced the disintegrating foam.
I guess there isn't much room for modding, but to be honest, they're already really quite good without any..... ok... maybe a little.... like new ear pads.... and arctic cotton instead of foam.

Well, GREQ, I also have to thank you for the pics. Now I see, why I could not take mine apart. PMB8 quite possibly is one of the hardest headphone to disassemble.
 
Here is what I am dealin' with right now:

 

[DefectiveAudioComponent]

  So here's something you don't see every day.
The guts of a PMB 8.
No headphones were harmed in the making of these photos 

 
  
 
  
 
  
 
  
 
I was able to successfully open both cups without making any (major) damage (a few tiny scratches).
I replaced the disintegrating foam.
I guess there isn't much room for modding, but to be honest, they're already really quite good without any..... ok... maybe a little.... like new ear pads.... and arctic cotton instead of foam.

 
Great work in getting them open

 
Did the driver rest on that foam ring, or was that just damping as well?
 
How about a close-up photo of that driver? There were a few variations on it after all.

 

[GREQ]

 
Did the driver rest on that foam ring, or was that just damping as well?
 
How about a close-up photo of that driver? There were a few variations on it after all.

Yes, the driver was pressed up against the little foam ring. I suspect without this, there would be a poor bass response, as this makes the seal.
 
Hmm.. I would have to open it up again to make driver pics. Actually I've got some spare time tomorrow morning, so expect them soon.
I probably should have at least shone a light through it or something first time round. 

 

[GREQ]

.

 

[ericj]

have you tried damping the front of that driver? 

 

[DefectiveAudioComponent]

With the driver mounted on the outside of the baffle, these PMB drivers present deep powerful bass without damping, and with a fully open back. However, comfort is slightly lacking....
 

 

[GREQ]

  have you tried damping the front of that driver? 

Nope.
From my experiences, front damping decreases treble, and sometimes increases bass and bass-bloat.
Might be interesting if by selectively damping the front I can isolate the areas of the driver that produces the most midrange and bass. 
More possibilities to explore. Yay.
 

  With the driver mounted on the outside of the baffle, these PMB drivers present deep powerful bass without damping, and with a fully open back. However, comfort is slightly lacking....
 

 that's one of the first things I tried when I got the U70 - just took the drivers out of the housing and held them up to my ears in the open air.
The sound was excellent... but my arms quickly got tired.

 

[nick n]

are you trying any variable dampings? Like rings  on the outer and letting the middle fly sort of thing? Or a disc over the center only?
 
"With the driver mounted on the outside of the baffle, these PMB drivers present deep powerful bass without damping, and with a fully open back. However, comfort is slightly lacking...."
that picture is showing earside then?
 
Interesting posts all thanks.

 

[GREQ]

  are you trying any variable dampings? Like rings  on the outer and letting the middle fly sort of thing? Or a disc over the center only?

Yup. Tried a few different materials in this way on the rear side of the dirver, but honestly, this had very little impact on the overall sound. 
 
The biggest changes I had involved paxmate and masking tape stuck DIRECTLY to the back of the driver.
The soft squidgy side of the paxmate directly on the driver back produced a very big hump in the lower mids/upper bass.
But sticking it down directly to the driver (leaving some breathing space) gave quite a strong bass sound.
 
Any form of 'heavy' damping over the entire driver (thick felt for example) was almost no different to lightly damping the entire driver, or even leaving it almost open.
So as you can imagine, getting any treble with the usual methods like heavy damping, reflectors etc was an exercise in futility. 
 
I think the next step will be a methodical selective closing of holes on both sides of the driver.

 

[ericj]

Yeah, i was never satisfied with my pmb100, but that is an open baffle. My hok-80-2 just needed firm damping and a sealed baffle, and sony pads.

.:Sent by pneumatic tubes

 

[iQEM]

need a favour here, do you guys, anyone, have some spare un-used YH100 driver?
i would buy for what's worth plus international shipping..
there's a local ortho user here on indonesia need 1 channel driver, since the stock one had died just all of sudden in mysteriously..Please kindly respond..


sincerely, your friend in ortho world..

 

[nick n]

Good luck on the YH100 driver, really hope you can find one.
 
ericj :
I see you mentioned your Hok were modded.
Do the V2 also have the rear disk inside to convert them to open or closed like the V1 do? Not yet opened them up. I suppose same stock thick grey wool type damping?
I find the V2 very enjoyable in stock form for now once the soft HD-25 pads were put on. Those pads fit perfectly ( aftermarket from Wang Yifei on ebay ) the pad lip is exact and very snug just over the Hok shells. No need for extra securing with tape/contact cement etc.
BTW stock I like it better than excruciatingly modded V1 thought what is there in the modded V1 is absolutely top notch.
 
I think I neeed help reinforcing my ortho disposition, lately I have been snared by the allure of a few key dynamics ( all vintage ), even though they are immensely enjoyable they are almost all lacking that special ortho speed and response, you know the thing that "makes them", I fear it is a slide that may get steeper, all I need from you people is a quick slap to the face to say "smarten up" and it might get me out of dynamicland.
Help. It is almost like I am downgrading. Much like the call of the Sirens only to be dashed against the rocks. Row row fight the powah!
 
BTW everyone, almost at 1.5 million views. That  is     nuts.  I am gonna secure that 1.5th view for myself....
maybe this time I will actually make a few t-shirts to send out to celebrate.
which brings me to my next point, why no free t-shirts when you spend 1k + on a headphone. It's the least a company can do.

 

[SeEnCreaTive]

Went to my dads to show him my t50rps, I tried explianing orthrodynamic was and why they are great, he goes on to complian about this old old pair he has and how terrible they are.... Then he mentions how much they weigh. I ask to see them and sure enough....



They are in PERFECT condition, other then the pads of course, sound OK, bass out the yingyang... But make sense considering they were designed when bass lacking records were prime

Before anyone asks... Heh, NOT selling them

 

[Tasoeur]

Went to my dads to show him my t50rps, I tried explianing orthrodynamic was and why they are great, he goes on to complian about this old old pair he has and how terrible they are.... Then he mentions how much they weigh. I ask to see them and sure enough....



They are in PERFECT condition, other then the pads of course, sound OK, bass out the yingyang... But make sense considering they were designed when bass lacking records were prime

Before anyone asks... Heh, NOT selling them

Nice pair, and indeed perfect condition ! 
 
I suggest you to try Jmoney beyer pads with these ! A great improvement in my opinion. 

+

 

[bluemonkeyflyer]

Went to my dads to show him my t50rps, I tried explianing orthrodynamic was and why they are great, he goes on to complian about this old old pair he has and how terrible they are.... Then he mentions how much they weigh. I ask to see them and sure enough....



They are in PERFECT condition, other then the pads of course, sound OK, bass out the yingyang... But make sense considering they were designed when bass lacking records were prime

Before anyone asks... Heh, NOT selling them

 
No Way! Those look great. They are easy to modify to control the bass and elevate the treble. 
 
Congrats and, "Thanks Dad!"