Asus Xonar U7 DAC and headphone amp Review

Contents
Introduction
Features & Specifications
Design, Build and Software
Performance
Conclusion

Performance

Now to the part that matters, the performance. We test it across music listening, gaming and watching movies.

Test Bench
CPU: Intel i5-3770K @ 3.8GHz
Mobo: ASUS Maximus Hero IV
RAM: Corsair Vengeance 8GB @ 1600MHz
GPU: Nvidia GeForce GTX 780 3GB
Audio Devices: Xonar U7 USB Audio, Onboard ALC898, Xonar DX
Speakers and Headphones: Head-Direct RE262 (IEMs), Audio-Technica ATH- AD700X (headphones), Sonic Gear Evo 7 2.1 speakers
OS: Windows 8 x64

Gaming

I find myself particularly excited to test the Xonar U7 with games, because of the way ASUS has marketed this product, and also because this is a gaming website. I chose to run the gaming tests across a variety of genres to test the U7 across the full gaming spectrum. Most games are recent, except Dark Souls: Prepare to Die Edition. Why I selected Dark Souls is because its subtle sounds effects play a big part in the immersion the game offers. Also, Dark Souls is the greatest game of our generation. (Click on the links for our Game Reviews)

Games Tested
Dark Souls: Prepare to Die Edition
Total War: Rome 2
Splinter Cell: Blacklist
Batman: Arkham Origins
Battlefield 4

The U7 performed as I expected it to perform with games. Mind you, I’m coming from a Xonar DX, which is a tad better in SNR numbers than the U7. Yet, I felt that the U7 separated sound effects better than the DX. The DX is not far behind though, as it provides a cleaner sound, but the difference is minimal. I used the Dolby software to set presets depending on the game. Available default presets are Racing, RTS, Action RPG and FPS.

The U7 provided a good soundstage in Dark Souls. Subtle breathing noises of a dragon resting in the backdrop of a level were visualized almost picture perfectly. The U7 particularly performed well in the high pitched sword slashes during combat. I felt a sense or airiness in Dark Souls, which I have come to believe is a signature of the U7.

Total War: Rome 2 was a different story altogether. I used the “RTS” preset in the Dolby panel for this game.  Maneuvering through the top-down world map was pleasing with the background music sounding crisp. When in real-time battle mode, that is when you see the U7 really shine. You can feel the thumping footsteps of large armies and cavalry. The soundstage again makes up for half of the experience. When an army charges down a hill and clashes with the opposition, the combination of numerous effects i.e. shouts, clinging of swords, firing of arrows; come together organically. It’s almost like you’re in the middle of the action. For RTS games, the U7 is the way to go.

Splinter Cell: Blacklist and Batman: Arkham Origins were tested using the Head-Direct RE262 in-ear monitors. The RE262s are famous for their crisp mids, but lack in deep lows, and the U7 made up for its shortcomings. Grenade blasts and gun shots in Blacklist come to life, sounding distortion-free in their full sonic range. Arkham Origins’ tense filled background score smudges well with environmental sounds.

For first-person shooters, most serious gamers use headphones to make sure they don’t miss out on subtle details like footsteps, weapon reloads, since it can make or break their game. For the same reason, I used the Audio-Technica ATH- AD700X headphones for Battlefield 4. These are a pair of audiophile grade headphones, and make a good match for the U7. Battlefield 4 is big on its explosions, and the headphones handled them well. These sound effects can give the best audio gear a run for the money, but the Audio Technica’s handled them well. My only issue was with the subdued highs. While the U7 performed well overall, I felt they couldn’t power the highs enough, even after trying different adjustments with the gain settings.

Music Listening

On paper, the Xonar U7 has numbers that could stand up against the better external soundcards in the market, and especially when compared to a laptop/desktop’s on-board soundcard. The 114 dB SNR is noticeable. You can make out the difference in quality when playing a low quality mp3 versus a high bitrate one. The Xonar U7 is rather punishing on low bitrate files.

I tested music with a mixture of FLAC, VBR and 320-bitrate files. While the difference between the three version is negligible, playing a 128-bitrate file will make its shortcomings visible brightly.

Listening to ‘Pinjda’ by Sanam Puri and Jonita Gandhi from Coke Studio Season 3, Sanam’s vocal range is extensive and requires a good combination of DAC + speakers for a desirable effect. The recording quality of this live track is not the best, but its not bad either. The U7 did a great job in presenting Sanam’s voice, with his vocal chord vibrations fully evident. Since Coke Studio is a live performance set, the soundstage puts you in the middle of the performance, as if you were in the studio itself. Yet, I still feel that the Xonar U7 performs well with good quality recordings and not so good with average recordings.

This is when I decide to perform listening tests on some good quality recordings, like Radiohead’s King of Limbs. The entire album is recorded with almost no use of sound FX, most sounds are produced organically. This where the U7 really shined. To put on paper, I’ll go as far as saying that they performed better than the Xonar DX, which has higher SNR numbers. Instrument separation was ecstatic, vocals appear balanced, almost as delicately as Thom Yorke’s voice.

Listening tests were performed at 24bit/192KHz, 16bit/44KHz and 24bit/96KHz