I get the picture of you using a 2" 4" 8" home stereo speaker. Is that right?
Well not impossible but improbable; in order to push a sound through anything you need enough push.
I could go on and on about the history of sound but take this to heart. In order to hear a sound it has to be from 60 decibels to 140 decibels..anymore and it won't matter.
Some hear different but you get the drift.
In order for speakers to produce those levels they have to have a good level of electricity or power to enable the speakers to sound. Too simple! OK!
I play heavy metal guitar through a Mesa 90 watt amp that goes to a 4 X 12" speaker Marshall cabinet. The Marshall is rated at 350 watts, do you think it will be able to take the Mesa 90 watt. No! Any amp can deliver more than what its rated. At full volume I could have the neighbors two blocks over call the police.
What all computers are missing is that amp. It's lucky if you have 5 watts on a sound card. Things are changing though. I here now you can hook your sound system with your computer for your entertainment center.
Microsoft is doing it. Not hip on that yet but its out there. Remember even that system still needs a amplifier.
Hope that helps,
Your Hardware Guide.