[IIIIIIIIIIIIIII]

I have been lurking these forums for a long time and have learned that open is preferred for its sound quality since the ear cups do not contain the noise. 
 
But open cans do no isolate well and are not ideal for libraries or noisy environments like trains. 
 
My idea was ear cups that telescoped out to become very large so the sound would not be as cramped on say a regular closed ear cup. The telescoped cup would still be closed at the end but it would be hollow inside. 
 
The reason for the telescope design was because of portability the ear cups could be collapsed back in to regular size and fit into a backpack, but telescoped out when listening to music in the train or library. 
 
Further if telescoped back in to the small size it would act like closed can and if telescoped to large size it would act closer to an open can ....I think?
 
Be aware that my picture is not very well drawn because I did it quickly, but I put labels on it. 
 
Also, I know this may come across as a joke to some of you especially because of my rank . But I must say that the idea of telescoping ear cups that are closed back to work as semi-open or open ear cups is a serious question of would it work.
 
If this idea in fact did work. The ear cups would look much more professional and the person would look more normal.
 
Again remember this is just a quick sketch poorly done only meant to get concept across. 
 

 
So my question is would the added space by telescoping a closed ear cup have any positive change in sound quality and would it be similar to that of open ear cup?
 
Edit: the telescoping feature could be locked at incremental extension points if that would also change sound signature.

 

[Taowolf51]

I think if you made the shape a cone, it would reverberate awkwardly.
Denon does something similar with their D2000/D5000/D7000 cans, except without the cone shape. And they have a pretty damn good soundstage (for a closed headphone).

 

[IIIIIIIIIIIIIII]

Quote:

I think if you made the shape a cone, it would reverberate awkwardly.
Denon does something similar with their D2000/D5000/D7000 cans, except without the cone shape. And they have a pretty damn good soundstage (for a closed headphone).

The cones would not be as narrow as they are in my awful picture, but from what you say about the Denons I wonder if telescoping ear cups really would improve the soundstage (something open cans are known for over closed cans). 
 
It would be interest if a company came out with a headphone with telescoping ear cups (albeit not as ridiculous as mine) that when extended improved the soundstage of the headphone while maintaining good isolation of a closed can.
 
I think as long as the cups did not cone out so narrowly and stayed rather cylinder shaped it could possibly work.
 
Maybe I just wonder why no company has tried to make any radical changes in the design of the ear cup to experiment with how it reverberates sound. Or perhaps they have and it turned out horribly. 

 

[fray92]

Quote:

I think if you made the shape a cone, it would reverberate awkwardly.
Denon does something similar with their D2000/D5000/D7000 cans, except without the cone shape. And they have a pretty damn good soundstage (for a closed headphone).

Yeah, they sure have decent soundstage but their isolations are on pair with open headphone...

 

[ProtegeManiac]

I see a few problems with this design:
 
1) You can collapse the cones into a backpack, but I wouldn't wear cones on the side of my head in public. It'll only be a matter of time before someone snaps my photo, processes it and makes my skin violet, and I'll be all over the net right next to the photo of that actual fictional villain with huge muscles, violet skin and black horns sticking out the side of his head (if anyone remembers who that is, I'd appreciate the info.)
 
2) Collapsible means it's likely to vibrate. That's why horns (the instruments) and similar instruments are one tube designs, not several layers of  increasing radius rings on the opening.
 
3) Any blockage on the rear of an open headphone is a lot like putting speakers with rear-exit ports right next to a wall.
 
Some headphones already employ semi-open designs, or are sealed with large, dampened interiors to simulate a larger enclosure and to minimize backwaves - the soundwaves that bounce off the back of the transducer, onto the enclosure, and then back onto the vibrating transducer - plus IEMs technology combined with Crossfeed are great for listening in noisy environments. Besides, will you be able to concentrate well enough to appreciate a great headphone in a noisy environment to begin with? As much as the noise might annoy you, chances are you're supposed to concentrate on what's going on. Nothing like getting run over, getting left by your plane/boat, or looking up to realize it's nearly closing time in the library and since you were sitting alone in an isolated corner, the janitor hits the lights and locks up, and he didn't hear you shout because he also has earphones on.

 

[IIIIIIIIIIIIIII]

Quote:

I see a few problems with this design:
 
1) You can collapse the cones into a backpack, but I wouldn't wear cones on the side of my head in public. It'll only be a matter of time before someone snaps my photo, processes it and makes my skin violet, and I'll be all over the net right next to the photo of that actual fictional villain with huge muscles, violet skin and black horns sticking out the side of his head (if anyone remembers who that is, I'd appreciate the info.)
 
2) Collapsible means it's likely to vibrate. That's why horns (the instruments) and similar instruments are one tube designs, not several layers of  increasing radius rings on the opening.
 
3) Any blockage on the rear of an open headphone is a lot like putting speakers with rear-exit ports right next to a wall.
 
Some headphones already employ semi-open designs, or are sealed with large, dampened interiors to simulate a larger enclosure and to minimize backwaves - the soundwaves that bounce off the back of the transducer, onto the enclosure, and then back onto the vibrating transducer - plus IEMs technology combined with Crossfeed are great for listening in noisy environments. Besides, will you be able to concentrate well enough to appreciate a great headphone in a noisy environment to begin with? As much as the noise might annoy you, chances are you're supposed to concentrate on what's going on. Nothing like getting run over, getting left by your plane/boat, or looking up to realize it's nearly closing time in the library and since you were sitting alone in an isolated corner, the janitor hits the lights and locks up, and he didn't hear you shout because he also has earphones on.

Thanks for the information. 
 
So basically instead of ridiculous cone-shaped ear cups the open sound quality can be achieved by adding dampening materials to the back of the ear cups?
 
What about instead of just dampening materials the cups were shaped so that soundwaves were reflected at an angle and also dampened so the soundwaves would not bounce directly off of the transducer? 
 
Or perhaps an ear cup with stalactite like extensions that would be placed in just the right spots to allow for optimal reverberation and sound quality?
 
I think my questions have been answered and I thank all of you for your thoroughosity. 
 
With that being said, I might just have to get myself a pair of cheap cans with big ear cups that I can take a part and fiddle around with by adding different cloths and materials to the ear pad.

 

[winkyeye]

The W1000X sound pretty much like open cans.

 

[FearSC549]

The best enclosure for a speaker driver would be a sphere because the distance of diffracting edges are different (in simple term, eliminate all internal resonances). I don't think people ever tried a cone, but I think it would work pretty well (think B&W's sphere & tube design). However, I don't think it would be a convenient set of headphones due to size and weight, and collapsible enclosure is out of the question (how can you get a rigid structure with that?).
 
Easy way is to get an average sized enclosure, something bigger than D2K-7K's enclosure and stuff the right amount of damping materials in there. Most likely you will end up with a pretty big soundstage, closed headphone.

 

[Taowolf51]

Quote:

Yeah, they sure have decent soundstage but their isolations are on pair with open headphone...

I wouldn't say that at all. When people listen to my D7000's, I can't hear a thing, even though they're right next to me. I've also asked people sitting at my table at work whether they can hear my headphones, and they say no.
I would put the isolation at about the same as my Pro 750's, maybe a smidge worse, but nothing more than that.

 

[obobskivich]

I don't think it would work - aside from the fragility of your collapsing cups (I'm thinking of those "portable cup" things you take camping), and the resonation, you wouldn't really be addressing the "problem" you've set out to solve. There are some "deep cup" closed headphones out there, the Headphile HD650 is one example, the JVC HP-DX1000 is another. I've personally heard neither, but they're both regarded as having fairly large soundstages. I know the Headphile phones are also regarded as being potentially resonant (why you'd want to close up an HD 650...). Alternately, there are headphones with fairly compact designs that present a convincing soundstage - the Denon series is one example, the Bose AE/AE2 is another, along with a number of Audio-Technica designs (And the Kenwood K1000, which likely has some AT in it). 
 
You don't need massive enclosures to create that - one thing most of these closed headphones have in common is angled drivers. 
 
Basically, you can't have your cake and eat it too - there are always going to be some design compromises made. Even at the absolute top end. 
 
Taowolf51,
 
You're talking about leaking, not isolation. How well do the D7000s prevent outside noise from coming in to you? They don't isolate very well. However, they don't leak that much either. Here's some graphics (just look at isolation, top right):
http://www.innerfidelity.com/images/SennheiserHD650.pdf (Open headphone)
http://www.innerfidelity.com/images/DenonAHD7000.pdf
 
 
 
Compare that with some more conventional closed/sealed headphones:
http://www.innerfidelity.com/images/UltrasonePRO900.pdf
http://www.innerfidelity.com/images/SonyMDRXB1000.pdf
http://www.innerfidelity.com/images/BeyerdynamicT70250Ohm.pdf
 
 
The Denons are a very good compromise between soundstage and leakage - they're very practical in an environment where others are near you while you're listening, where something like the HD 650 would not be. They don't block a lot of outside noises though. 
 
 
 

 

[WaLaoEh]

This thread made me laugh real hard.. xD

 

[ProtegeManiac]

Quote:

Thanks for the information. 
 
1. So basically instead of ridiculous cone-shaped ear cups the open sound quality can be achieved by adding dampening materials to the back of the ear cups?
 
2. What about instead of just dampening materials the cups were shaped so that soundwaves were reflected at an angle and also dampened so the soundwaves would not bounce directly off of the transducer? Or perhaps an ear cup with stalactite like extensions that would be placed in just the right spots to allow for optimal reverberation and sound quality?
 
I think my questions have been answered and I thank all of you for your thoroughosity. 
 
With that being said, I might just have to get myself a pair of cheap cans with big ear cups that I can take a part and fiddle around with by adding different cloths and materials to the ear pad.

1) It won't be exactly the same, especially if you have the same driver in two different enclosure designs, BUT it is possible to get close enough. For one, they make drivers that are designed for closed and open enclosures from the get-go - look into speaker enclosure designs and you'll see subwoofers and mid-bass drivers designed for small enclosures, and some, for both small enclosures and free-air. Check out car audio, and how people cram dampening materials on the inside of their car doors, or install the drivers in small fiberglass enclosures all over the front just to find a good spot that minimizes phase issues.
 
2) Possible but it would be too complex to design and manufacture, which will make it expensive, since the drivers can just be designed to work on a smaller sealed enclosure as above. Think of Ultrasone Edition 8, the downside is you can buy a whole system based on the HD600 for the same money. I mean, sure, maybe a good chunk of that isn't for the RND and manufacturing of the drivers, but for Ethiopian lambskin leather and machined cups, plus the 'exclusivity' of limited production, but eventually we might have more drivers like this. IF it won't cost me an arm I'd have one though, so I still think Ed.8 owners are getting their money's worth; it's mostly the prospect of eating cup noodles for a year that stops me.
 
If you really want to try the DIY route, I suggest you learn to work with wood and fiberglass, that way you won't be limited to cheap sealed cans that will only take a given driver size. Install the drivers at an angle to your ears, like the T1/T5P and HD800, etc, or use K701/702 angled pads, and make the cups out of wood or use wood for the frame and then use fiberglass, making sure the diameter can mount pads (like how the Headphile C-pads are designed to take Beyer pads), and line the interior with this and then stick this on that, or just the last one if the fiberglass is rigid enough.
 
 

 

 

[Taowolf51]

Quote:

Taowolf51,  
You're talking about leaking, not isolation. How well do the D7000s prevent outside noise from coming in to you? They don't isolate very well. However, they don't leak that much either. Here's some graphics (just look at isolation, top right):
http://www.innerfidelity.com/images/SennheiserHD650.pdf (Open headphone)
http://www.innerfidelity.com/images/DenonAHD7000.pdf
 
 
 
Compare that with some more conventional closed/sealed headphones:
http://www.innerfidelity.com/images/UltrasonePRO900.pdf
http://www.innerfidelity.com/images/SonyMDRXB1000.pdf
http://www.innerfidelity.com/images/BeyerdynamicT70250Ohm.pdf
 
 
The Denons are a very good compromise between soundstage and leakage - they're very practical in an environment where others are near you while you're listening, where something like the HD 650 would not be. They don't block a lot of outside noises though. 
 
 
 

I bunch leaking and isolation into one, usually. Sorry for the confusion.
 
Honestly, I haven't noticed a huge difference in isolation either. My office is pretty loud (we have a set of huge concert speakers that is playing music all the time), and I don't really hear any of it. I don't really blast my music either. Usually people need to wave in my face or turn off the lights to get my attention, which was true with the Pro 750's as well.
 
I just did a little test by wearing them (without music) and clapping, I then tried the same with the Pro 750's. The difference was pretty small, but I'd give the nod to the Pro 750's. But it isn't a huge difference, I'd say. Of course, I've never owned a pair of open cans, so maybe they isolate far better than I think they do. All I can say for certain is that they do block out quite a bit of outside noise. Maybe not as much as my Pro 750's, but it isn't anything like, say, not wearing headphones at all.
 
I'm not saying that they have great isolation, I just don't think its terrible (in my experience, at least).