Headphones vs loudspeakers

Something not being mentioned here is "efficiency". Headphones are going to be much easier to driver than typical passive speaker systems, through passive crossover networks and such. Also, yes, woofers driving a larger space are not as efficient overall - unless you get more woofers in volved, and likely active woofers at that.
Then, of course, yes, acoustics of the room come into play, associated equipment choices, set up, etc.
You should always consider variables when considering any medium, factor, issue, etc.

the same issue goes for car system efficiency vs. most home setup's. The woofers are not only closer to so many boundaries in relation to wave length - that they are reinforcing more of the bass frequencies- but the size of the woofers in relation to the amount of air is a much greater precentage. Again, efficiency for dynamic potential is higher in this "pressure pot" situation. It's likely a simmilar situation with the headphones, I pressume

..on another point regarding headphones.. Most headphone jacks are of poor quality, and the circuits are afterthoughts. To get the best from headphones, they need a dedicated headphone amp.

Stringreen: even with mid-fi non dedicated head phone amp the sound through head phones is better (with better tonality and fine dynamic shadings) than many high-end set ups. That is the dilemma. One more thing: though head phones many mediocre recordings become listenable --> I simply hear much more details through the phones. Of course the sound gets better with better head phone amps.

Chris

I wonder about the ambiant noise level in your listening room. It may be masking the details of your speakers. Headphones have close proximity to your ears and anywhere from a little to a lot of isolation. This can make it easier to hear details.

I've got excellent headphones, AKG K701s driven by a Woo Audio WA6 single-ended, class-A amp. You can see my speaker rig in the link below my name here. Anyway, I judge the health of both systems by how close they are to each other. They are very close in all respects, including detail. For the best listening on the speaker system I keep the ambiant noise level low, often turning off the AC, making sure the dishwasher is off, etc.

Dave