[headphone man07]

Hello there, I may have added an overly ambiguous title so define a little more, I'm looking at what makes headphones loud, what gives them their frequency spectrum subjects like that, please explain it to me like I'm an alien from whatever planet the aliens come from, oh and don't simplify it, explain in full detail please, to make this simpler, I'm going to put down some topic titles and leave you to answer them please do this in one post, thanks in advance guys.
1)What makes headphones loud (only headphones i.e. no talking about the source)
2)What gives headphones their frequency spectrum i.e. which aspects and what needs to be changed to create them
3)What makes headphones sound detailed and clear
The last one isn't really related to this but, me and one of my friends were having a headphone argument (he isn't an audiophile) but basically, he said that if you listened to music for a long period of time at a reasonable volume you could damage your ears, I said that only applies to decibel levels higher up the spectrum and that it's a sort of thresh-hold but the topic name for this one is
4)Can you damage your ears with headphones without having them on high volume
(assuming this is for someone who doesn't get ear infections or has any hearing related problems which might mean their ears are already 'fragile' to start with)
Thanks in advance
P.S. I'm not an alien from whichever planet aliens come from and from I point of view of headphones I answer more of the what, less of the why. 

 

[jaddie]

Quote:

1)What makes headphones loud (only headphones i.e. no talking about the source)

One set may be louder than another for the same volume setting of the player or amp for several reasons.
1.  They are more efficient at converting electrical energy into sound energy
2.  They are designed to have the electrical property of lower impedance, meaning they are able to accept more electrical power at a lower voltage, and accepting more power translates to more volume...usually.
3.  They couple to the eardrum better, like an in-ear design vs an outside the ear design. IEMs usually need very little power to be loud. 
4.  They may have a frequency contour that emphasizes an area of spectrum that ears are most sensitive too, which makes them seem louder, but perhaps less natural
Quote:

2)What gives headphones their frequency spectrum i.e. which aspects and what needs to be changed to create them

The sonic character of headphones is arrived at by choices in design, including materials, housing size and shape, the deliberate creation of a frequency contour with acoustic design, just to name a few.  Any or all of those could be changed and adjusted by the designer for the desired result, and perhaps even more.
Quote:

3)What makes headphones sound detailed and clear

A recent study by Sean Olive at Harmon International determined that people prefer the most natural sounding headphones.  The lack of artificial "color" or emphasis of a particular part of the spectrum helps headphones and speakers sound natural and neutral.  When that happens, they will sound balanced and clear too.  Clarity, by itself, is often coupled with emphasis in the mid and high frequencies, but over-emphasis of clarity will also result in un-natural sounding headphones.  Good neutral balance is the most important aspect.  Detail should come along for the ride with balanced sound.
Quote:

The last one isn't really related to this but, me and one of my friends were having a headphone argument (he isn't an audiophile) but basically, he said that if you listened to music for a long period of time at a reasonable volume you could damage your ears, I said that only applies to decibel levels higher up the spectrum and that it's a sort of thresh-hold but the topic name for this one is
4)Can you damage your ears with headphones without having them on high volume
(assuming this is for someone who doesn't get ear infections or has any hearing related problems which might mean their ears are already 'fragile' to start with)

The risk of hearing damage is a combination of duration of exposure and volume level.  The higher the volume, the less time it takes for damage to occur.  Thus, we can't really talk about potential damage by listening without talking about specific volume levels.  "Reasonable" won't do at all, because we don't know what that is. 
 
Human speech at face-to-face distances averages about 60-70dB SPL (Sound Pressure Level).  Listening to anything at normal human speech level will not damage hearing, and the exposure time will be limited by how long the conversation can go on without somebody falling asleep.  At higher levels, like 85dB SPL, you've shortened your safe exposure time to a few hours.  The chart on this page shows permissible exposure time vs levels, the graphic on the right shows examples of sounds at those levels for comparison.
http://www.dangerousdecibels.org/education/information-center/decibel-exposure-time-guidelines/
 
One problem with headphones is that they all tend to block some outside noise a bit, so we loose reference of how loud they are really playing.  There may be a tendency to play headphones a bit louder than we should because of that.
 
Pretty sure you are from another planet, though.  How many ears do your headphones have to fit on?   I think your friends the Pleadeans still have only two...you?