These days, every motherboard has integrated audio, and usually a decent surround chipset. So why would you buy a sound card? This is the question Asus’ Xonar D2 must answer, especially as it costs well over $200. Possible responses include better sound fidelity, or features such as ASIO 2.0 drivers, while gamers could be after hardware acceleration for immersive sound technologies such as EAX 5 or improved surround sound.
Various members of Creative’s
X-Fi range satisfy all these needs, but they’ve slipped up with Windows Vista, which no longer supports hardware Direct3D acceleration: Creative’s EAX system operates through the Direct3D API. The newer OpenAL system does work with Vista, though, and games are switching over. However, Asus is putting its money on the fact that the next generation of gaming consoles will use Dolby Digital and DTS, and most PC games are ported from consoles.
In other areas of surround sound, Asus matches Creative feature for feature. Whereas Creative has its Multi-Speaker Surround-3D system, Asus supports Dolby Headphone and Virtual Speaker for quasi-surround experiences from headsets and stereo speakers respectively. The conversion of stereo to surround uses either Dolby Pro Logic IIx or DTS NeoPC. One area in which Asus wins is that the analogue results can be encoded back to AC3, and output via S/PDIF to an external decoder – something Creative’s X-Fis can’t do.
The Asus has benefits for audiophiles, too. The signal-to-noise ratio is very high, quoted as 115dB for recording and 118dB for playback. Creative’s mainstream X-Fis offer only 109dB, and even its flagship Elite Pro runs to just 116dB. Similarly, while the Xonar can sample at up to 192kHz, Creative’s X-Fis are capped at 96kHz. The Xonar also has a feature called Analogue Loopback Transformation, which allows you to feed the analogue output into the input without a physical cable. This enables you to record even copy-protected DRM files. Asus supplies a Portable Media Processor utility to help with this, although, naturally, it stresses this must be used for legal file backup only.
Comparing it with a Creative X-Fi Elite Pro on a variety of music, the Xonar achieved richer audio, particularly in mid-range frequencies. However, while the Asus supports EAX 2 under Windows XP, DirectSound3D limits its abilities with Windows Vista. OpenAL games ran fine, but EAX 2 titles such as F.E.A.R. sounded flat, and the much-vaunted Dolby- and DTS-based equivalents have yet to arrive in any numbers. In contrast, Creative has developed ALchemy, which translates EAX to OpenAL. So, while the list of supported titles is far from exhaustive just yet, X-Fi cards can still provide atmospheric effects for older games using EAX 2 and DirectSound3D.
On paper, and from our tests, the Xonar is very capable and the sound signal is as clear as the specifications suggest. However, its usefulness revolves around how important you consider EAX. Asus has a point in that only a handful of titles support EAX 5, while most still opt for EAX 2 or are moving to OpenAL. However, the Xonar’s commendable attributes must be weighed against its hefty price. For many, this will be too much to pay for the extra sound fidelity and surround-processing options.