Why do headphones sound so good...

They get into your head with the music in a way that is unique.

There's no room to distort the sound on its way to your ears.. That really does a lot!

Other than that, phones are much cheaper to produce (but not necessarily simpler). To get the best out of a good pair of phones you still need a high quality source, amplification and great cabling however. When you do have that though, they're hard to beat. :)

No, the truth is there are no room bonderies or reflextions off walls and furniture that impeds sound reproduction from sounding its best. But not all of us are comfortable with this type of listening, but if you are enjoy.

I have found that headphones sound different, not always better. Since you do not have to deal with room acoustics, it is easier to design a good set of full range headphones. These are easier to drive and do not have the amplification requirements of speakers as well. Most people do not give speakers enough power. Meshing the speakers with a sub is another difficult task.
For what it's worth, I love my headphone setup. There are so many things it excels at. I still find myself listening to speakers more than headphones. The stereo separation in headphones can be unnatural on many recordings, and you don't get the full experience where you feel the music as well. It makes a bit of difference. Hard to describe.
Of course to get a speaker setup on par with a good headphone setup, costs about 5-10X as much.

I strongly question your presumption, that they do indeed sound better. I've had both (AKG k1000, Senn HD650, etc.) and a few speaker systems. There's no way headphones can replace a speaker system. Headphones are good for not waking up your neighbors or roommates. That's it.

1) Less air to move
2) Less air to move
3) Less air to move
4) No room acoustics to affect sound

Headphones move so little air that they usually outperform most consumer speakers in terms of distortion. They also help cut out or reduce ambient noise. For critical listening or adjustments, headphones are very useful....but the sound is awful!

Unfortunately we learn from birth to have an awareness of space (natural reverberation) from the way the brain processes the signals reaching the ear. (If you step into a anechoic chamber it can actually be nauseating as your eyes tell you something that your ears contradict!)

Unfortunately headphones sound far from natural - they seem claustrophobic or closed in or like the sound is coming from "within your head". The brain correctly detects the spatial information in the stereo sound as coming directly from one side or the other and following a line through your ears into your head. In essence, the brain figures out that the source is not from the front, above, behind or underneath but directly from the sides; so the sound image just seems to pass through your head from side to side (the band is playing in your head).

Basically the diffractive role of the pinea is negated in this configuration.

I agree that headphones sound awesome. I have Sennheisers and they are wonderful. Detailed, open, great bass and seem to make most every recording sound much better than thru all but the best speakers. They don't replace my speakers but when I really want to "get into" music, I put on my phones!

Well Amplifying an Ipod through a good resolution system will never sound as good as it going through headphones #1, To much exposure to the lower quality source in most cases...

I thought I would never beat headphones myself, mainly they are just easier and you can get good quality cheaper, and main thing is you are not fighting the acoustics of a large room and airspace, they are 1" from your ear drum, huge difference.

However after many battles, I have found the solution that stomps my Grado's, and thats Excellent room treatments with very efficient speakers and tube amps... Now I feel like I have more pressure and smooth controlled sound than even with headphones, and yes it even sounds better like a live venue in the house.. I have people tell me all the time they can't believe how clear and balanced even compared to headphones my system is now.

So room treatments will be like the earmuffs sealing to your ear if your willing to truly solve the issues with an audio system, its 9 times out of 10 the room environment not the speakers, and thats where the headphones have one up in the first place, cause they don't compete with a crappy room!

Why do headphones sound so good...
Although the responses thus far seem diverse, I can honestly say that I agree with every single one of them to at least some degree. To add to the already excellent insights given above (not a loser in the whole lot, imo), I would say:

--Headphones USUALLY are able to retrieve more sonic detail than all but the very finest loudspeakers, as Itball mentions.

--In my experience, headphones do NOT provide a convincing soundstage, presumably for the reasons Shadorne alludes to.

--I personally own both Stax Lambda Signatures AND Stax Lambda 404's (it's a long and embarrassing story as to why I own both sets of cans....), and the speakers I own seem to outperform them in every arena-probably even including retrieval of detail(although I'd like to do more critical listening to test this point). That is saying a lot considering the legendary status of these headphones--Stax makes only one model of higher caliber, which is the Omega II's.

I agree with most of what has been said here regarding both the pros and cons of headphone listening. Just depends on your preferences, and I’m willing to accept their limitations; everything has weaknesses. Personally, I do all of my critical listening through headphones, and I couldn’t be happier. They involve me more in the music than any speaker-based system ever did—and I’ve owned some hyper-expensive ones. Granted, I’ve got a pretty costly rig, but, still, it’s a fraction of the price of my last speaker system.

I believe that it is much easier to reproduce life-like dynamics with phones than with speakers, probably for the reason oft stated above, that there is less air to move. Some experts believe that it is the gulf between the dynamics of live versus recorded music that make it easiest for us to discriminate between them. If that is true, then it follows that phones would get there easier than speakers and be preferred by many.

I also agree with most all of the above.

I would add excellent headphones have very little phase shift, as their single diaphragm moves nearly/almost as one solid piston through the range of 200Hz to >8kHz.

In that same range, most all speakers have hundreds of degrees of phase shift (time delays), which change with the frequency being reproduced.

A lack of time-domain distortion can also be called a high level of time-coherence. This is not the same as phase coherence.

Time-coherent operation goes a long way to revealing the touch on any instrument, the enunciation and inflection in any voice, intense dynamic contrasts, and clarity of the individual artists, almost regardless of what those headphones might be plugged into.

I use the word 'any' in the last sentence, for you should be able to track those characteristics of the performance through any tone range/any performer. Also, any image, as odd as it may be to hear it inside your head, should be stable in any tone range.

If you encounter a tone range where something isn't right about one of those characteristics, you are in a range where phase shift and possibly other distortions are high.

My first truly involving headphones were Koss ESP-9's. Still have them, now with a dead power supply, but someday...

Best regards,
Roy Johnson
Designer
Green Mountain Audio

I would add excellent headphones have very little phase shift, as their single diaphragm moves nearly/almost as one solid piston through the range of 200Hz to >8kHz

In that same range, most all speakers have hundreds of degrees of phase shift (time delays), which change with the frequency being reproduced.

Roy,

Agreed. Minor and gradual (smooth) changes in phase seem to be extremely important in tranducer design between about 300 and 4 Khz (preserving timbre over the senstive mid range frequencies ).

I suspect this is one of the reasons speakers with similar frequency response sound so different. I suspect that another reason stems from differences in off-axis response or dispersion.

So two alike speakers in on axis frequency response can sound totally different. So why do the audio magazines and specs all look primarily at on axis freq response?....go figure!!!

Other factors are IM and harmonic distortion ( again something audio mags rarely delve into and are often horrific in many speakers at higher or realistic listening levels and especially at low frequencies but also, suprisingly, bang in the upper mids/treble where it is most audible (ringing, breakup)...again nobody seems to look at this....go figure!!!)

Further factors are baffle and edge diffraction.....again nobody examines or measures these effects as a test on commercial products....again ....go figure!

BTW: I still have my trusty AKG 240's (1979 vintage Stucio headphones), the first headphones that really blew me away. I think the Koss were stunning too - although I found them a bit heavy/uncomfortable to wear. (However, I do find headphone listening an unnatural sound even if distortion is more easily heard. It is not just the "in your head" sound but the lack of reverberation that I don't like... a certain reverberation of a live room is quite essential, IMHO, in hearing more detail in the music as the reverberations help seperate sounds and let the brain/ear gleen more - so I rarely use headphones as a good pair of loud speakers simply wins hands down!)

Right on all counts, Shadorne.

Best regards,
Roy Johnson
Designer
Green Mountain Audio

They don't sound good - you are simply not used to real live music.

Music can be felt as well as heard, especially the lower frequencies. With earphones music cannot be felt. Earphones usually lead to irreparable damage to hearing as the users turn up the volume to compensate for this loss.

Live music also carries an acoustic signature of the room. Using speakers you have a similar effect. Earphones rob you of this.

Regards
Paul

I love my headgear but it doesn't touch my main speaker system. The headphones appearingly more detailed lack the substance given by a decent pair of speaker with decent electronics. One reason headphones may appear asttractive is that you can play them louder than the average speaker system if you live with others. I really like my headgear but I love my main system. I like the effect of the sound of speakers in a room. Headphones lack the body and weight of decent speakers. I have an HR-2 Emmeline amp and Sennheisser HD650 headphones so my headgear does not lack warmth or body but my Hales with my Pass electronics simply have more of a good thing. If your room makes your speakers unlistenable then headphones are the obvious solution but if you can beat the room then nothing beats loudspeakers.