I can only tell you my experience. The leap from onboard sound to outboard sound with an M-Audio sound card was extraordinary. I have great hearing, and consider myself an audiophile, but the difference was monumental.
The most important thing is the quality of your speakers, and how critically you listen. I run an original set of Klipsch ProMedia 2.1's. I later added an M-Audio Revo 7.1 dedicated sound card. I could notice a big difference b/c it's S/N ratio was so much greater than the on-board sound. I...
Looks like they went from a discrete power amp with separate output transistors, and power supplies, to a chip amp. How does the new set sound? I wouldn't expect as good.
I think you're missing the point. Great s/c, no s/c, these speakers sound fantastic. That's all that matters. I have a kick ass s/c as well, but if I wanted to buy a great set of speakers, bypassing my s/c wouldn't make a difference.
If you want to spring an extra $50, and bass isn't your most important consideration, you may want to review these:
http://www.maximumpc.com/article/reviews/bowers_wilkins_mm1_computer_speakers_review
Prices here...
These have received rave reviews:
http://www.audioholics.com/reviews/speakers/lifestyle-desktop-and-portable/b-w-mm-1-multimedia/build-quality-features-setup-remote
http://www.maximumpc.com/article/reviews/bowers_wilkins_mm1_computer_speakers_review
There are other online reviews. Google B&W...
I bet the mids, and highs on those would be awesome. If you're not big into bass, I'm sure you'll be thrilled. It would be nice if they showed some specifications.
If it were me, I always buy speakers first, and build around them. I'm running an old set of Klipsch 2.1. I had these for several years before I updated my sound card from inboard, to an M-Audio 7.1 Revo. The difference was very noticeable in a positive way.
It's too bad I couldn't find that same track on youtube, to compare them side by side. I would think the artists themselves would have a HUGE problem with them changing the sound of their recordings......
Not really. The Corsair PSU all have on/off switches.
http://www.corsair.com/power-supplies/modular-psus/professional-series-gold-2/ax750w.html
Click the pic and check the rear view.
http://www.gradolabs.com makes some of the best $60 head phones around. They're not well known in the PC world, but in the audio realm they've long been recognized.
Here is a link to a review done on the price range you're looking at...