What is the purpose of making headphones open?

I really have no idea, but this is a possible guess:

Background info: Generally a speaker with an 'infinite baffle' meaning it's essentially like the speaker is mounted in a wall where the sound radiating forward hits the listener far before it would hit the end of the plane it's radiating from and the sound radiating backwards is separate (like in another room).  This prevents box acoustics and diffraction from affecting the speaker as much as possible.  Since for most people an infinite baffle is impossible an enclosure is substituted and tuned in conjunction with the crossover so that it has minimal effect.  Sometimes an enclosure is used to the design's advantage, but many times it's a compromise.

I believe that an open pair of headphones works somewhat like an infinite baffle speaker.  The sound radiating backwards does that - it radiates away and there are no reflections or anything to change the response of the speaker.  This is especially beneficial because headphones don't have the luxury of crossovers to tune the response of the drivers (though theoretically you could put a crossover in a pair of headphones... another time).  The downsides of this approach are reduced isolation and reduced bass.  High end headphones can make up the bass (at least somewhat) by high end drivers with better FR.  High end headphones also put SQ over all/most else and thus the smoother FR of open headphones is a worthy trade off for little to none isolation.

Closed headphones will have reflections from the backside of the headphones that will affect the sound of the headphones.  How detrimental to the sound (or possibly positive) this effect will be depends on the reflecting surface, the driver, etc.  Note that just because a headphone is closed does not automatically make it worse than an open.  A well designed closed headphone can and will be better than a poorly designed open - ex D7000.  It's all about trade-offs and the skill of the compromiser (designer).

I'm not sure why AD700 is better for gaming/movies.  It might just be the design lends itself to those because of all of the complex variables interacting.  It may not be simple to answer.  It could be it's increased bass due to the bass reflections inside the headphones, or perhaps the increased isolation distancing you from the real world and into the game/movie's world.

I could be completely wrong, but figured I'd post this educated guess.

loudspeakers are not open, and they do "work".

some older closed phones like the r10 or cd3k kill most open phones in the 3D SS department...I also have no idea why all the mfg's go open now...ppl wanna use headphones to be isolated, call them "ear speakers" if they're opened, duh.

Quote:

Originally Posted by leeperry 

loudspeakers are not open, and they do "work".

 

some older closed phones like the r10 or cd3k kill most open phones in the 3D SS department...I also have no idea why all the mfg's go open now...ppl wanna use headphones to be isolated, call them "ear speakers" if they're opened, duh.

I'm not sure if this was directed at me or High_Q, but I don't believe I said that loudspeakers are open.  I said that an infinite baffle gives a smoother FR than many enclosure designs because of lack of standing waves, reflections, edge diffraction, etc. and that open headphones might be trying to emulate the qualities of an infinite baffle.  I might've implied that speakers don't work, but that was not my intention.  Speakers obviously can work very well.

Not everyone uses headphones for isolation.  What about someone living in an apartment who wants to be able to listen to their music at night?  They might not need isolation, but they can't blast their tunes on speakers and therefore headphones are used.  At the same time, this isn't an argument to use open headphones by itself.  I'm just pointing out that isolation may not be a priority for some headphone users.

Calling all open headphones ear speakers and all closed headphones headphones is a valid point, but I think the current naming scheme works and therefore see no reason to change.

Quote:

Originally Posted by leeperry 

loudspeakers are not open, and they do "work".

 

 

Electrostatics are....

Originally Posted by xxbaker 

I'm not sure if this was directed at me or High_Q

It wasn't directed towards anyone specifically tbh, I see this thread as a brainstorming exercise...and it's a fact that some vintage closed cans kill newer open ones in the 3D SS and low end bass response departments.

You got a valid point that some ppl don't want isolation, I personally see headphones either as a way to dive into your own egoist bubble or for a singer to record vocals...and I believe that the engineers that are unable to make a closed can sound wide and clear are just unskilled...or their company doesn't have enough cash flow to do some proper R&D around psycho-acoustics and go for a quick buck using the laziest solution: opening the cups back.

It's like those ppl who like to finish arcade games in one single credit...they could press CONTINUE, but they don't. Make it tough or refrain altogether

although speakers are not open at their back side,they still operate in an open environment (room of some kind) and not speaking right towards the ear like headphones.  for this reason i think that we can relate speakers as open design and not close.  

it is also known that closed headphones are much more difficult to design and enginner in order for them to sound right, becasue of the "sound reflections" mentioned earlier by xxbaker.

you can easily dampen inner resonances: http://www.dynamat.com/products_car_audio_dynaxorb.html

all you need to get a wide SS is big cups to allow the drivers to breathe...reason why Larry makes those deep cups

Quote:

Originally Posted by leeperry 

you can easily dampen inner resonances: http://www.dynamat.com/products_car_audio_dynaxorb.html

 

all you need is big cups to allow the drivers to breathe...reason why Larry makes those deep cups

it is true leeperry,i am not an expert on this but i am sure that big cups help with the frequencies.  but still...as big as they will be,it is still not "open air" and everywhere when playing music in a close room you need equalizing of some kind.  in an open enviorment you don't need equalizing at all.

most of those closed phones have tiny vent holes on the sides to allow the air to be used like on a bass-reflex system....but there's a far cry between a fully open back and tiny vent holes

those companies don't make closed phones coz they don't know better, and open phones sell...so why bother?

xxbaker is right. An infinite baffle would be the best speaker principle if it was practicable: no rear sound waves interacting with the direct sound waves and no standing waves within the cabinets. Speaker cabinets are compomises. With headphones such a compromise is unnecessary (except when isolation is a concern). Closed headphones suffer from reflections from the back of the housing which get mixed to the direct sound – the main reason for their limited soundstage, as I see it, since soundstage is a product of preserved spatial cues (read: intact transient subtleties), and adding reflected sound to the direct sound corrupts them.

Yes, you can, but you won't succeed. It's impossible to avoid audible standing waves in speaker cabinets, so how should it be possible with the comparably tiny amounts of damping material in headphone cups! You inevitably get multiple reflections, although the damping material will reduce them to a lower number of multiple reflections.

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you can easily killer inner resonances:

you can get a much wider SS on a cd3k than on a HD650...the former is closed, the latter is open...it's all about psychoacoustics and cheating the brain, like the Ultrasone S-Logic that provides a 360 degrees SS to some ppl w/o angled drivers and w/ tiny cups at that!

(See edited post above.)

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One of the main reasons for the abundance of open phones is the fact that it is easier to make an open phone sound good,it is very difficult to make good closed phones,so the manufacturers take the easy way out.

And in case we forget the R10 is a closed phone that all open phones are still trying to catch up to,but never will.

Quote:

Originally Posted by leeperry 

you can easily killer inner resonances:

 

you can get a much wider SS on a cd3k than on a HD650...the former is closed, the latter is open...it's all about psychoacoustics and cheating the brain, like the Ultrasone S-Logic that provides a 360 degrees SS to some ppl w/o angled drivers and w/ tiny cups at that!

You're talking only about resonances. Resonances arent the only effect which influences the sound in this context.

Also, dynamat only works within a relatively small bandwidth and it has a limited effectiveness. It doesnt eliminate resonances, it dampens some of them.

Open enclosures in principle are definitely superior, but remember that even open headphones are usually only open on one axis (the sides are still reflective to varying degrees - with the exception of the K1000), but more problematically, its virtually impossible to get enough low frequency (sub-40hz) displacement without using impractically large drivers.