Listening to the Xonar U3
Before getting into listening tests, let's fire up RightMark Audio Analyzer to get an objective sense of the Xonar's analog signal quality. RMAA's loopback test simultaneously plays and records a sample clip before rating performance in a number of categories. The Xonar U3 was tested against my Acer ultraportable's integrated audio, the Xonar DG, and the onboard audio from a Gigabyte microATX board based on AMD's A75 platform hub for Llano APUs. RMAA was run at the highest quality level supported by the Xonar U3: 16 bits at 48kHz.
|RightMark Audio Analyzer audio quality - 16-bit/48kHz loopback|
|Frequency response||Noise level||Dynamic range||THD||THD + Noise||IMD + Noise||Stereo Crosstalk||IMD at 10kHz||Overall score|
|Gigabyte A75||Excellent||Very good||Very good||Very good||Good||Very good||Very good||Very good||Very good|
|Xonar DG||Excellent||Excellent||Excellent||Very good||Good||Excellent||Excellent||Excellent||Excellent|
|Acer 1810TZ||Very poor||Good||Good||Average||Poor||Very poor||Very poor||Average||Poor|
According to RMAA, the Xonar U3 has a better frequency response, less distortion, and less crosstalk than the notebook's built-in audio. However, the DG and Gigabyte motherboard both score higher in virtually every category.
RMAA has a graphing function that allows us to examine the Xonar's performance in greater detail. First, let's look at how the frequency response curves compare.
As you can see, the notebook's frequency response is about as erratic as Charlie Sheen's recent behavior. The Xonar U3 offers a much smoother frequency response curve with none of the violent oscillations exhibited by the 1810TZ.
Look at the Gigabyte motherboard and the Xonar DG, though. Their frequency response profiles are much flatter overall—especially at the high end of the spectrum.
RMAA's intermodulation distortion graph tells a similar story with a different set of squiggly lines. Versus the notebook, the Xonar U3's audio signal is clearly less distorted. But put it up against the DG and integrated motherboard audio, and suddenly the U3 doesn't look so hot.
The same holds true when we focus on dynamic range. While the Xonar U3 is an improvement over the Acer ultraportable, the desktop competition comes out ahead yet again.
Of course, probing signal characteristics only tells one part of the story. Listening tests are a better arbiter of sound quality, and I've conducted several back-to-back sessions with the Xonar U3 and both the Acer notebook's integrated audio and the X-Fi in my primary desktop rig. I used Koss' PortaPro headphones when comparing the U3 to the notebook and a set of Abit iDome speakers when pitting the USB Xonar against the desktop config. The analog audio outs were used in all cases.
I had intended to spend the bulk of my flights to and from Computex in Taipei, Taiwan switching back and forth between the notebook's headphone jack and the Xonar U3. It didn't take long to grow dissatisfied with the ultraportable's music playback quality, though. The built-in audio feels flat and lifeless; bass lines lack punch, high notes are a little dull, and the middle of the spectrum sounds muddled and distant. The Xonar is a huge improvement on all fronts and across multiple musical genres. Ultra-high-bitrate MP3s ripped from Tori Amos, Rob Dougan, Nine Inch Nails, Johnny Cash, Radiohead, and The Postal Service CDs sounded substantially better on the Xonar. The U3 also lacks the faint background hiss I've detected with integrated audio solutions on the 1810TZ and a few other notebooks and motherboards.
Versus my desktop's X-Fi, the Xonar isn't a clear-cut favorite. It sounds good, no doubt, but doesn't stand out as being better. To be fair, I've always liked the vocal bias exhibited by the X-Fi and other sound cards based on Creative audio processors. The U3 sounds a little more even while maintaining the hints of extra vocal and percussive oomph inherited from the Xonar DG. I just didn't fall in love with it in the same way.