Headphones through speakers

[BLG]

I'm just starting to get into computer audio so this may be a stupid question but... Is there a difference if I run my headphones through my 2.1 speakers vs being directly into my sound card.

if it matters I have Altec Lansing VS4121BLK speakers

Edit: To go along with this, if I have an input on the front of my case hooked up to my sound card as well, and i have my speakers hooked up directly to the soundcard and my headphones hooked up to the front input (which is also attached to the sound card) would there be any negative affects?

 

[kagebarton]

chances are the sound card isn't putting out a strong enough signal to really properly drive your headphones, and your speakers will have an amplified headphone jack

 

[JonnyBlazexx]

I have the klipsch 2.1's. They have a headphone out that is amplified, which I like very much. Sometimes its more convenient to plug into the port on the front of my PC that is connected straight to my audigy 2 zs, and i have to turn the volume up to like 80-90% to watch movies comfortable, at this volume when there is silence i hear a distinct hissing

 

[kagebarton]

there probably won't be much damage to anything, but i always go for sound quality so i'd always use the externally amplified ports