Performance and Testing - Continued
For testing here I primarily used the direct 6-channel line outputs to the corresponding inputs on my Logitech system. Why not just use digital? It is supposed to be the better option after all. Well, yes it is better at transporting multi-plexed audio conveniently using just a single cable, though this convenience comes at the price of digital compression. You see, whenever an audio signal is transported digitally it must have some compression applied. So for the purist stick to the direct analog outputs, and maybe even think about upgrading the cables.
The RightMark Audio Analyzer 5.6 included in the package is a great little tool designed to verify the integrity of signal paths between audio devices in your system, this also being a nice subtle way for ASUS to prove what's written on the box. This handy little program allows you to analyze a test signal and have it appear as a graph.
In this image I have analayzed a 96KHz 32-bit test signal to give an indication of the Xonar's response curve. I have also listed here some results from a couple of test sweeps at different quality levels. Firstly we have a relatively low resolution of 16-bit paired with the sample rate you would find on most music CDs. The results are quite impressive, with special attention given to a very respectable THD figure.
The second sweep uses a higher resolution of 24-bit with a very high sample frequency of 192KHz which is the highest industry standard at the moment; definitely a handy little program to play around with, though a little unstable at times.
16bit 44khz RMMA
Frequency response (from 40 Hz to 15 kHz), dB: +0.01, -0.07
Noise level, dB (A): -91.9
Dynamic range, dB (A): 91.9
THD, %: 0.0009
IMD + Noise, %: 0.0075
Stereo crosstalk, dB: -92.1
24bit 192khz RMMA
Frequency response (from 40 Hz to 15 kHz), dB: +0.02, -0.08
Noise level, dB (A): -107.5
Dynamic range, dB (A): 107.5
THD, %: 0.0007
IMD + Noise, %: 0.0022
Stereo crosstalk, dB: -104.0
Playback of material mastered in high definition (like some audio CDs purchased over the internet from other countries) support this resolution during playback and offer superior depth and integrity to transients over their standard resolution siblings. It wasn't until the Xonar was paired with my Logitech 5400s that the true detail of "Live" HD recording could be realised. Not only is the increased resolution noticeable, but the separation between instruments is fantastic when the Xonar's DACs start to really come into their own.
When considering this card purely as a gaming solution things are not quite as rosy I'm afraid. Through no fault of their own ASUS have been restricted to using EAX 2.0, which as we all know has been out for some time now, as we are seeing titles with EAX 5.0 support. Creative would face substantial loss of revenue if later versions were released as "open source" to competing manufacturers.
So what does this mean? Well it means that as far as supporting the latest algorithms from Creative Labs the Xonar is about on par with most run of the mill cards on offer. Of course the onboard DACs are going to be far superior to most generic cards but for gaming you want the latest support for many reasons. It's not that the Xonar cannot be recommended for gamers, as it certainly can be and does still offer supreme fidelity whenever it's called upon.
Having said that I sincerely doubt ASUS have had any intention of designing this card purely from a gaming standpoint, if alone the software bundle is any indication.
So it seems ASUS are left with their hands tied behind their backs on this one. While I did find gaming performance to be of a high quality whatever the situation when using the Xonar, I simply cannot recommend it over one of the latest evolutions from Creative when it comes to the hardcore gamers, because the support simply is not there, and won't be any time soon if Creative continue to lead the way in 3D algorithms with their in-house EAX still remaining the standard of choice for most developers.
However, with support for the latest incarnations of real-time multi-channel encoding by Dolby Labs and DTS in 5.1 or more channels it's going to be interesting to see whether developers for the PC gaming sector take up on these offerings which have (let's face it) been developed primarily for the XBOX 360 and PS3 home entertainment markets, and are yet to have a significant impact on the PC arena.
Windows Vista is limited to Direct Sound at the time of writing, although I would not imagine a great deal of punters would be using Vista to game prior to SP1 release anyway.
When it comes to playback of surround sound material there is very little the Xonar cannot do, supporting just about every playback mode imaginable; although not physically being a Dolby Digital or DTS decoder it is possible to use Pro Logic IIx or DTS NEO to encode a stereo signal into five or more channels and then export the encoded data digitally back out to a decoder, something not possible on cards available from competitors.
When it comes to playback of multi-channel movie sound tracks, the Xonar manages to get the job done comfortably with tests being passed without hitch nor lack or support, and both Dolby Labs and DTS Labs have full support with ASUS and the Xonar.