[fengwei007]

I’ve had quite a few headphone amplifiers, some of them rated as high as 4W @ 16 Ohms (Burson Soloist) while some rated as little as 10mW (EARMAX Pro), and many in between. I’ve also had many headphones (HE6, HE560, HE500, LCD2, HD800, HD650, HD600, T1, T5p, DT880/600Ohm, TH900, TH600, D7000, W3000ANV, ESW10JPN, ESW11LTD …) to work with these amps. Most of them sound very nice as long as the power is enough. I even tried most if not all of them on HM901 portable player with pretty good result. The only difficult ones are the HE6 (most amp can’t even make it sound loud enough) and T1 (sound very dry and thin on some amps), the rest are pretty easy to drive, including the HD800 which sounded pretty well even with EARMAX Pro.
 
From what we’ve seen here and many other reviews, most suggested to have very high power output for those Hifiman headphones or headphones like T1/HD800. But theoretically we only need like 1-5mW real power for these headphones to sound loud enough to make you deaf, and from my own experiences, most headphone amps are powerful enough to drive pretty much any headphone minus very few like HE6/T1.
 
I also play speakers, and have some hard to drive Dynaudio speakers (4Ohm, 86dB/w/m sensitivity). I’ve seen many users use some amps w/ 1000 or even 2000W output powers for these speakers, but I use an amp with about 140W output with my speakers, they sound pretty fine, I don’t think I need any more power than what my amp already has. Some speaker users talk about the 1st watt: as long as you can give the speakers a very good 1W power, most speakers should/would sound well enough to most users.
 
Here are my questions:

• Even these power hungry speakers can sing w/ 1W power input, why we need as high as 4W for headphones?
• Are some (if not all) headphone amp ratings over rated? I don’t feel the Burson Soloist has 4W output since the HE6 still asks for more to sing when paired with the Soloist, but I don’t think HE6 needs 4W power to sound to its full potential (even hard to driver floorstand speakers can sing with 1W power). Or is it because the output power varies a lot because the load changes?
• I have a Lake People G109P and Yamamoto HA-02 w/ me right now. The G109p has output of 2.3W @ 50Ohm load, the HA-02 only rated 300mW @ 50Ohm load. But I feel the HA-02 is A LOT more powerful than the G109p when paired with HD600/HE6/HE500 (these are the headphones I have at hands right now). And the HA-02’s speaker output (rated at 240mW with 8 Ohm load) can make the HE6 sing almost as well as my Marantz PM8003 integrated amp (rated 70W @ 8Ohm load). Is it because the G109P is over rated or the HA02 is under rated?

 
I also read somewhere that our headphones don’t need a lot power, as long as we give enough power (a few mW) to the headphones, they should sound good. But most place said the otherwise.
 
These are just my thoughts and experiences. Wonder if you guys had similar questions or experiences.

 

[MindsMirror]

If you have an amp capable of 1W into speakers with a sensitivity of 86dB@1W, you would theoretically get a maximum output of 86dB. That is a fairly loud average listening level. However, almost any audio you will be listening to has transient peaks above the average level. Music can easily peak 15dB higher, and maybe more in very dynamic music or movies. If you want the amp to handle 15dB peaks without distortion, you need 32 times more power.

 

[fengwei007]

If you have an amp capable of 1W into speakers with a sensitivity of 86dB@1W, you would theoretically get a maximum output of 86dB. That is a fairly loud average listening level. However, almost any audio you will be listening to has transient peaks above the average level. Music can easily peak 15dB higher, and maybe more in very dynamic music or movies. If you want the amp to handle 15dB peaks without distortion, you need 32 times more power.

Ok, that makes sense. Thanks for the reply