[fellgrail]

I'm using a M-Audio Fast Track C400 as a sound card.
 
The specs (found elsewhere on Head-Fi, can't find them anywhere official):
 
- Headphone Output (D/A)
Max Output Level into 32 Ohms: -2.0dBV at THD < 0.03% into 32 ohms
Power into Ohms: 20 mW into 32 ohms
Channel-to-Channel Crosstalk: < -70dB
SNR: -104dB, A-weighted
Dynamic Range: 104dB, A-weighted
Frequency Response: 20Hz to 20kHz, +/- 0.3dB
Working Range: 24 to 600 ohms
 
And for headphones, I'm using the Audio Technica M50s. 
 
Type: Closed-back dynamic
Driver Diameter: 45 mm
Magnet: Neodymium
Voice Coil: CCAW (Copper-clad aluminum wire)
Frequency Response: 15 - 28,000 Hz
Maximum Input Power: 1,600 mW at 1 kHz
Sensitivity: 99 dB
Impedance: 38 ohms
Input impedance: 47kOhm
Weight: 284 g (10 oz) without cable and connector
Cable: 1.2 - 3.0 m (3.9' - 9.8') Coiled, OFC litz wire
Connector: Gold-plated stereo 1/8" (3.5 mm) connector with strain relief and professional screw-on 1/4" (6.3 mm) adapter
Accessory Included: Protective pouch
 
 
With this information, is it possible to do any damage to my headphones at the maximum output of the C400? 
 
What specific statistic matters in this kind of comparison? 
 
I would like to use the M50s as 'speakers' at some points during my editing process, and it would be much more convenient to simply be able to turn the volume up on the C400.
 
 
As far as I can tell, at maximum volume from the C400, there isn't any kind of degrade in sound quality from the phones. 
 
Any help is greatly appreciated. 

 

[higbvuyb]

Apparently the M50 can handle up to 1.6W, more than your card can supply. Though you should be really careful any time you turn the volume up in case you accidentally put them on and blow up your eardrums.
 
You'll also lose all your bass if you use them as speakers.

 

[Claritas]

I have read that you can damage the drivers using very high volume for a moderate amount of time. Unfortunately, I don't remember the source and explanation.

 

[jcx]

manufacturers often aren't clear on power rating - the 1.6 W is likely a "won't melt the voice coil" rating
 
it is still possible for low frequency, high input to push the voice coil/diaphragm, suspension too far - stuff might start banging together that was never meant to touch or stretch the suspension too far
 
sometimes you can hear clatter as the voice coil former bottoms against the magnet structure - may be other mechanical interferences from too large input at low frequency depending on construction details

 

[kraken2109]

In most cases you would damage your ears long before you damage your equipment.