Superb sound quality across the range, especially for something this small and a USB device at that.
Dolby Headphone - done right with all 3 modes for choice.
Dolby Pro-Logic IIx for stereo/5.1 to 7.1 upmixing.
USB like size, very easy on the table - no clutter.
Dolby Digital Live real-time encoding over TOSlink Optical out
Outstanding surround sound with Dolby headphone in 7.1 playing games/movies (more on this below)
The flat non-DSP effects sound of this card is warm to neutral depending on your headset. And with equalizer tweaks it sounds great on highs and perfect in the lows. Bass is not over powering yet just at the right level. Even bass freaks will be happy with it's bass, granted the equalizer can give out more bass if needed but then over doing it can muffle the bass more, also dependent on your headphone/headset. The mids are also great. I trust my ears, not the RMAA analyzer.
Great Stereo sound, thats all fine. What about surround sound? This is where this little gizzmo truly shines. The surround is not muffled or hollow sounding, its just perfect and the best part is that equalizer settings can tweak the feel even more. Positional audio is impressively immersive and accurate.
I tested the THX Tru Surround on the X-Fi 5.1 pro, Sharkoon's own SCU hardware solution and the Xonar U3 in game and movies.
In games they all sound great, but Xonar U3 sounds more natural with positional accuracy so good that you can really tell the various angles from where the sound is coming from with your eyes closed. Proper audio cues. Sharkoon's SCU is good in positional audio but there is something about the over all sound that makes it more like a small sound stage, only slight though. THX was accurate as Xonar U3 in positional cues but the sound quality is no better than the Sharkoon SCU.
In movies the THX Tru Surround is terrible because its using only two channels, switching it to 5.1 in windows panel make sounds just getting lost over non-existent channels. Sharkoon is digital input so no such troubles. Xonar works fine as 7.1 set in windows or from the Xonar Control panel. You can select 2,4,6 or 8 channel mode from the click of a drop down menu.
Other Thoughts:
A little background into why I needed a USB sound card anyway. I got this Sharkoon X-tatic SR surround sound headset and then recalled my M18X alienware will not output a 5.1 dolby digital signal over SPDIF. Its just Stereo PCM. TBH I should have given it more thought before buying the headset. But believe me the headset was very good and worth the investment. So I got the Creative X-Fi 5.1 Pro USB
The X-Fi 5.1 Pro USB is good on stereo sound quality and does what I want which is optical out with Dolby Digital live encoding over TOSlink optical. Works fine with the Sharkoon's SCU sound box with optical input feed, Dolby headphone surround sound through the Sharkoon's SCU sounds great.
But getting the Xonar U3 made the X-Fi and the sharkoon's SCU totally redundant, it simply has a more robust Dolby Headphone implementation with ability to select the 3 modes of Dolby Headphone DH1, DH2 and DH3. You cant do that with the SCU of the Sharkoon or any other product for the most part that uses a dedicated Sound box, with the exception of the [size=small]JVC[/size][size=small] SU-DH1 Dolby adaptor.[/size]