[Armaegis]

But would you rather have the wedges be a soft absorbent material? A hard surface, even a corrugated one, will probably reflect too much. Hmm, or maybe have a parabolic shape to direct all the reflections to an absorbent focal point... maybe?

 

[Rick]

I always had the idea of something resembling a one way valve (like in a water system, or heck, human veins), where the rear wave can enter into the dampening chamber,  but then simply is dampening and bounced around from dampening structure to dampening structure until there is nothing left, and has no exist point, and cant go back the way it came.

 

[JadeEast]

Quote:

 I've never seen anything but smooth cup interiors, though, many with parallel walls. 

I'm pretty sure that I did see that the Sony MDR-R10 had difusion surfaces on it's interior cups. 
 

 

[wualta]

Well, at least Sony believes me. Not that this is necessarily a good thing.
 
Anyway, the wedgies wouldn't have to be themselves absorbent, as they would be in an anechoic chamber. In a headphone cup there's no room. So you just break up the interior of the cup with random-sized facets and you make the cup asymmetrical so it doesn't support any particular frequency or its harmonics, and you fill the cup with fiberglass. Then you have a multi-reflective surface which sends the backwaves scattering in all directions, and if they don't get eaten up by the fiberglass filling on their way out of the driver, they get bounced back through the fiberglass several more times randomly. Nothing coherent gets reflected back into the driver, like someone taking a flash photo of themselves in a mirror. The multi-reflective surface increases the length of the path the backwave has to take through the absorbent stuffing, increasing its efficiency.
 
So the ideal closed ortho cup would be asymmetrical and rough'n'chunky on the inside. Maybe.

 

[wualta]

Quote:

Hmm, or maybe have a parabolic shape to direct all the reflections to an absorbent focal point... maybe?

This is not a bad concept. You could also simply angle the back of the cup to reflect the backwave downward into a big cup o' fiberglass. The Marantz 'stat did something like this, though it was vented.
 

 

[JadeEast]

Here is a patent from the Sony cans. I know I saw an article that showed pictures of the ridges inside the can but can't find it at the moment. 
 
http://www.google.com/patents?id=R-0ZAAAAEBAJ&printsec=abstract&zoom=4#v=onepage&q&f=false 

 

[ericj]

Quote:

Yes, and has anyone considered the resonance properties of  headphone cups made of rock?
 
More seriously, some sort of synthetic rock, like Corian?

Polk made some "home theater" speakers made of some sort of resin that they claimed to have the same acoustic properties as granite, back 'round the turn of the century. Eldest sister's 1st husband had a set, received as part of a deal to review some equipment for a magazine somewhere.
 
After a month or so he moved the polk 'front' speakers to the rear, reinstalled the speakers he built from a kit in college as fronts, and used the polk rears as bookends or something.

 

[wualta]

Yes, just because something's heavy doesn't mean it doesn't resonate or flex. Making something truly nonresonant is, as the ThunderPanzers and T50RPters have found, tricky. But a small rock should qualify. Shape is part of it. For example, if Polk simply replaced MDF boards with fake-granite boards, I'd expect problems. Some thinking outside-the-cabinet was called for in that instance.

 

[ericj]

They were like Minimus 7's made of heavy molded resin instead of something else. A little bigger than the 7's, but not a lot.
 
Come to think of it, the main difference between them and some of the later permutations of the M7 was probably the guy in the lab coat. 

 

[wualta]

Does Old Matthew still prance around in that lab coat from the now-ancient ad campaign?

 

[momomo6789]

Quote:

Well, at least Sony believes me. Not that this is necessarily a good thing.
 
Anyway, the wedgies wouldn't have to be themselves absorbent, as they would be in an anechoic chamber. In a headphone cup there's no room. So you just break up the interior of the cup with random-sized facets and you make the cup asymmetrical so it doesn't support any particular frequency or its harmonics, and you fill the cup with fiberglass. Then you have a multi-reflective surface which sends the backwaves scattering in all directions, and if they don't get eaten up by the fiberglass filling on their way out of the driver, they get bounced back through the fiberglass several more times randomly. Nothing coherent gets reflected back into the driver, like someone taking a flash photo of themselves in a mirror. The multi-reflective surface increases the length of the path the backwave has to take through the absorbent stuffing, increasing its efficiency.
 
So the ideal closed ortho cup would be asymmetrical and rough'n'chunky on the inside. Maybe.

ill try it out once my leg is less broken ive seen the inside of r-10s but i didn't really pay any attention to it if anyone has any pics.
 
if anyone has any ideas for ortho or thunderpants cups i have nothing better to do. give me a pm with any ideas.

 

[Rick]

Lightly dampened, open cups, and cut out a plunger to suction to your head around yours ears for ear pads!
 
 
*edit*  that was a joke, really. 

 

[ujamerstand]

unibody wooden shell, open back, and find a way to mount the orginal headband to the cups.

 

[sachu]

Wualta, the uneven texture on the back of the cups make a whole lot of sense. Do you guys suggest a method of trying this out in cups that already have a relatively smooth surface to break up reflections better? The midrange and especially imaging can only get even better with this am sure. 
 
And this reminds me, i need to send the TPs out to you again sir as i truly feel they are much better sounding that they were whence you received them in the loaner program. Still a very closed sounding can, but damn does this sound good. Nearly two weeks of not listening to the LCD-2 straight..The Liquid Gold in its current configuration is a much better match with the TPs than the LCD-2..nuff said!!

 

[Planar_head]

Quote:

Wualta, the uneven texture on the back of the cups make a whole lot of sense. Do you guys suggest a method of trying this out in cups that already have a relatively smooth surface to break up reflections better? The midrange and especially imaging can only get even better with this am sure. 
 
And this reminds me, i need to send the TPs out to you again sir as i truly feel they are much better sounding that they were whence you received them in the loaner program. Still a very closed sounding can, but damn does this sound good. Nearly two weeks of not listening to the LCD-2 straight..The Liquid Gold in its current configuration is a much better match with the TPs than the LCD-2..nuff said!!

What about some kind of clay?
Just throwing that out there. It was the first thing that came to mind to prototype a surface like that.