You could consider an external card like a Sound Blaster Omni or Recon 3D. Alternatively a DAC and Amp. An external card like one of the ones mentioned will have the advantage of doing virtual surround. With a DAC and amp combo you can get the best possible audio, but the sky is the limit when it comes to pricing.
Edit: I've got an Omni too.
I have some powered Sony desktop speakers that are a step up in price bracket from yours (though I haven't used them at all in the past 3 months), almost universally the headphone jack on these external speakers is cheap and noisy... It should be a little better directly plugged into the X58, but even so the amps built into soundcards aren't very clear and also have to contend with even more interference from other electrical parts.
I like the Omni because it's basically an external soundcard. It offloads the sound processing load from the CPU (more resources for other stuff), has a better DAC and Amp than what's built into any motherboard, and easily allows you to connect to upgraded amps or DACs later. It will also be the hub to let you connect headphones and up to a 5.1 speaker setup, and switch outputs in software without having to unplug anything. I like the virtual headphone processing very much.
A hi-fi amp will still improve on the sound, but my K712 sounded very good plugged directly into my Omni.
I think you guys sold me on the omni. I was going to purchase the ZxR but the problem was that with my xeon and 3 video cards I do not have anymore slots available.
Is the recon3d a lot better? if so I will spend the extra $50 for it since the OMNI and recon3d also seem to solve my problem of not needing another microphone!
EDIT: Seems the Omni is the only one with a microphone. So I take it I should go that route. I take it more expensive here does not mean better?
Edited by bombadilio - 4/22/14 at 6:51pm