But in my previous review I noted that the Auzen X-Fi Prelude 7.1 behaved differently. Its precision degenerates without improving the other characteristics. Thus, I recommend you to stay in the Entertainment mode for listening to music if you have a Creative X-Fi card and don’t want to change the chips on it. Hardware conversion into another sample rate is implemented very well on the X-Fi, and the resulting sound is better than with bit-per-bit playback at the clock generator frequency of 44.1kHz.
But what about the Xonar? Can it benefit from resampling if it’s got a mixture of NJM2114 and RC4580 chips on its front output? I tried to switch the frequency selection option in the ASUS Audio Center at first but couldn’t hear any clear difference. The vocals only got muddier in some recordings. Then I tried to use WinAMP with the ASIO output plugin and my doubts left me: the resampling into 192kHz with the Ultra quality gave me the space the lack of which I noted above. It makes the high frequencies softer and more detailed and adds some more dynamics. The differences are not as conspicuous as with the Creative X-Fi Elite Pro but quite noticeable.
The same plugin helps measure the sound of the rear outputs which use the same DACs but three RC4580 opamps on each instead of the front output’s two NJM2114, one LM4562 and two RC4580. Has this cocktail a reason? It has indeed. Without resampling, there is a loss of detail on the rear channels, the high frequencies are fuzzy, the bass is not deep. But all these things improve greatly when you resample into 192kHz: the rear channels are still inferior in high frequencies and bass but I would appreciate them higher than the front output as concerns medium frequencies and the overall openness of the sound. The combination of three types of operation amplifiers in the front output makes it sound somewhat gloomy and cramped.
By the way, I can tell you a few interesting facts from the life of the ASUS Xonar. When you set the analog output into 2 Speakers mode in the Audio Center, the signal for the rear outputs is mixed into the front channel even if you use ASIO. On the contrary, if you select a multi-channel configuration but do not enable Dolby Pro Logic IIx or DTS Neo: PC technology, a stereo signal with a sample rate of 44 and 48kHz transferred through the Windows audio interface (including ASIO) is duplicated in the rear channels. For some reason the sound volume is lowered by 3 and more decibel for every interface, save ASIO, in the multi-channel mode.
The subjective description might have ended at that if it didn’t dawn upon me to check out the quality of the audio cables included with the ASUS Xonar. When I connected the sound card to the amplifier with one of them, I had to perform the tests once again because the sound became different: smaller details got clearer, the room acoustics became more realistic. There was the space that had been lacking. The coloring of medium frequencies disappeared. Surprised at that, I checked out a few more cables and each differed from the others. And I had to listen to each sound card again with five different cables.
After long experiments I came to the conclusion that the Monster Interlink 200 cable I had used before ruined the Creative X-Fi Elite Pro with its already sharp sound. When I used the cable enclosed with the C.E.C. amplifier the coloring and high-frequency problems disappeared although the cymbals and the sibilants in vocals still jarred on the ear. It was overall more comfortable, yet the card revealed its full potential in the Entertainment mode only: the stereo panorama got broader and more natural. The medium frequencies were clear and detailed. The high frequencies remained somewhat too gaudy, though. The ASUS Xonar sounded better with the included cable as it had less coloring and better microdynamics. The card easily coped with music of any genre, even with such complex classics as the infernal dance from Stravinsky’s Firebird, and the Story of Prince Kalendar from Korsakov’s Scheherazade. In the overture from Verdi’s Macbeth many sound cards fail to cope with the women’s choir, transforming the voices into indistinct deafening shouts. The Xonar not only separated each voice in space but also played the whole composition without any distortion which would make me lower the sound volume. Still, the ASUS Xonar is not ideal. My preference lies with the Auzen X-Fi Prelude as soon as it comes to lyrical compositions. Its way of reproducing music has something that I haven’t found a name for. It is a tenderness that attracts you, a softness that doesn’t make you tired. Interestingly, the Auzen X-Fi Prelude is the only card not to suffer from the Monster Cable although another tester I called for assistance from could distinctly tell between the cables even with this card.
For those who don’t believe that the cable can affect the sound of your equipment, I publish the measurement results for the chain Creative X-Fi Elite Pro → cable → CEC HD53R → ASUS Xonar D2. The amplifier was connected to the sound card’s line input with a very short cable with two mini-jacks.
Having checked each sound card with dozens of musical compositions, I have to confess there is no clear leader among them. Each card has it unique character. With a good audio cable the Creative X-Fi Elite Pro can sound superbly in Entertainment mode, being just as good as the ASUS Xonar D2 in terms of details and size of the sound scene. The Auzen X-Fi Prelude 7.1 is inferior to both its opponents in terms of macrodynamics but surpasses them in natural timbres and aftersounds. The ASUS Xonar D2 seems to me a golden mean in terms of bass reproduction. It has a fantastic resolution, but its medium and high frequencies are somewhat synthetic (this effect reduces when you use resampling into 192kHz).
The last step of my aural tests was the operation of the card with headphones without an additional amplifier. To remind you, ASUS declares a high-quality headphones buffer in the Xonar D2. In fact, it is a front output cascade based on paired general-purpose opamps, identical to those employed on the step of conversion and filtering of the three additional analog outputs. However, the buffer does its job well, making the card sound excellent even with the Grado headphones whose impedance is 32 Ohms. It’s hard to hear the difference from an external amplifier: there are just fewer details, a smaller depth of the scene, but the stereo panorama doesn’t get any worse as is the case with most sound cards that are not meant to connect to headphones directly. On the downside is the lack of power of the operation amplifiers. At 100% volume the output signal voltage drops by over 10dB when you connect your headphones. As a result, there is no reserve of volume even with highly sensitive headphones. Of course, you can lift up the individual volume controls of each channel in the Xonar D2 Audio Center mixer but then you’ll hear the volume lower distinctly at the first notes of a musical composition.