ASUS Xonar Essence ST/STX soundcards Page 3

The Xonar Essence STX was doing sterling work for my everyday listening. How would it stack up against other computer-audio solutions?

My first comparisons were with a slightly more expensive product, the $300 Logitech Squeezebox, which accepts audio data over a WiFi or Ethernet link, but is limited to 16 bits resolution and a sample rate of 44.1 or 48kHz. Source was the Squeezebox Server program (originally called Squeezecenter) playing files from the iTunes library on my Mac mini, and levels were matched to within 0.1dB at 1kHz.

Ah, that's what I was missing with the Xonar card—a remote control! And the joy of having a display that I can read from my listening chair. But the Squeezebox's sound, with its standard power supply, fell a little short of the Xonar Essence's. The bass lacked extension and the highs were grainier. When I played the master files of my recording of Cantus's While You Are Alive (CD, Cantus CTS-1208), the soundstage for Eric Whitacre's Lux Aurumque was less well developed, the hall sounding a bit smaller and drier.

The second round of comparisons were against a product that has become our de facto standard for high-end computer playback: Ayre Acoustics' QB-9 D/A processor ($2500), which features a USB input operating in the jitter-eliminating asynchronous mode (see Wes Phillips' review in October 2009). Again the source was my iTunes library, this time played from the Mac mini using iTunes, controlled with my iPod Touch via Apple's Remote app, and levels again matched at 1kHz.

Well, as much as I want to tell you that the $200 Xonar Essence equaled the $2500 Ayre, it didn't. Low frequencies had even more authority, high frequencies were silkier, and the Essence's soundstage was revealed as being flatter, with less image depth than with the QB-9. Yes, the iTunes-Mac-Ayre combo is irritating in that every time you want to play a file with a different sample rate, you have to exit iTunes, reset the sample rate in the Audio/Midi setup utility, then reopen iTunes. But the sound from the Ayre on hi-rez files was up with the very best. And, of course, the QB-9 will handle 88.2kHz files in a bit-transparent manner, though it won't, without a forthcoming firmware/hardware upgrade, decode files with sample rates of 176.4 or 192kHz.

But in the immortal words of the inestimable Sam Tellig, there was simply more there there with the Ayre. On "North Dakota," Lyle Lovett's duet with Rickie Lee Jones from Live in Texas (originally CD, Curb MCAD-11964), the delicate space around the electric guitar solo and the congas was more easily resolved through the QB-9, with both instruments being set farther back in the stage as a result. The Essence was very good, but the QB-9 was all I could imagine wanting or needing. For 12 times the price, of course.

Headphone listening
That the Xonar Essence cards have a dedicated headphone output is a boon for late-night listening. And the fact that their maximum output level can be adjusted to match the impedance and sensitivity of your 'phones is a blessing. I don't have the space here to go into the cards' sound quality with headphones—I will do so in a Follow-Up—but suffice it to say that the Essences did well in this mode.

Summing up
The Xonar Essence STX and Essence ST soundcards are by far the least expensive way of turning a PC into a genuine high-resolution audio source I have yet encountered. Neither the Essences' resolution nor their low levels of noise are compromised by having to operate in the electrically unfriendly environment of a computer chassis.

Assuming that the problems I encountered using the Xonar Audio Center to play files at 96 and 192kHz were specific to my computer/operating-system setup, both cards worked reliably, and using the ASIO4 virtual playback device (or later, the Wasapi driver) did resolve those problems. However, given the increasing number of high-quality files being offered for download with sample rates of 88.2 or 176.4kHz, their omission is a major impediment to my giving either of these cards a universal recommendation. And the fact that the Essences are compatible only with PCs is a problem for those who, like me, have found the Mac a more friendly environment for playing music from a computer. But for playing back CD-sourced files, I can unreservedly recommend the Xonar Essence, in either of its guises, as the least expensive means of extracting true high-end sound from a PC.

ASUSTeK Computer Inc.
US distributor: ASUS Computer International
44370 Nobel Drive
Fremont, CA 94538
(812) 282-2787