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ASUS Xonar U1 USB Audio Station

Date: November 28, 2007
Author(s): Matthew Harris

Own a notebook and not impressed with the onboard sound solution? Would you like the ability to be a bit more “hands on” with your audio? Do you want something that’s different than what everyone else has? ASUS might just have the answer for you.


ASUS recently jumped into the computer audio arena in a big way with the release of their Xonar D2 (and now D2X PCI-E). Rory took that card for a spin a few months ago and was left thoroughly impressed. In addition to offering fantastic audio reproduction and low distortion, it included a great software bundle and was well presented.

Once the D2 model was released, we found out that both a PCI-E and USB version of the card were en route. The USB “Audio Station” is arguably the more interesting of the two though, as it’s designed to offer superb external audio for both desktop PCs and notebooks with the help of EAX and DirectSound HW acceleration, all while having reasonable specs to boot.

How impressive could USB audio be? Because of the external nature and limited capabilities of the USB connector, it’s no surprise that the common audiophile don’t take USB audio too seriously, whether it be a sound card or head phones. We will evaluate potential issues later, but for now let’s take a peek at what the U1 brings to the table, shall we?

Audio Performance
Output Signal-to-Noise Ratio (A-Weighted): 100 dB
Output THD+N at 1kHz (A-Weighted): 0.0045% (87 dB)

(-60dB, A-Weighted) 96 dB
Dynamic Range: 96 dB

Analog Playback Sample Rate and Resolution: 48 KHz
Cross-talk (10Kohms, 1KHz) -104 dB

Headphone Amp
THD+N< 0.005% @ 47 mW x2/ 32ohms
THD+N< 0.006% @88 mW x2/16ohms
96 dB SNR
>1.1Vrms full-scale output voltage for >8 ohms load
Frequency response (-3dB/48KHz): 20~20 KHz for 32 ohms
(headphone with 8~150 ohm @ >10mWx2 recommended)
Audio Processor UA100
I/O Ports
Bus Compatibility: USB
Analog Output Jack & Digital S/PDIF Output Combo: Analog 2CH/Digital 5.1
Analog Input Jack: Yes, stereo recording
Driver Features
Operation System: Windows Vista (32 & 64 bit), Windows XP (32 & 64 bit)
Dolby® Technologies: Dolby® Headphone, Dolby® Virtual Speaker, Dolby® Pro-Logic IIx, Dolby® Digital Live
DirectSound3D Game Extensions 1.0/DirectX: DS3D GX 1.0 supports EAX gaming sound effects and DirectSound 3D hardware enhanced functions on Windows Vista. (DirectX/DirectSound 3D compatible)

Smart Volume Normalizer™: Normalizes the volume of all audio sources into a constant level and also enhances your 3D sound listening range and advantages in gaming

Magic Voice™: Modifies the sound of your voice, for VOIP and online chat applications

Karaoke Functions: Music Key-Shifting and Microphone Echo effects

Xear 3DTM Virtual Speaker Shifter: Virtual 7.1 speaker positioning

Array Microphone: Reducing environmental background sounds and noises; keeping your front side voice input as clean as possible

Other Effects: 10-band Equalizer/27 Environment Effects

Bundled Software Utility Portable Music Processor Lite: Add Dolby Headphone, Dolby Virtual Speaker (w/ Pro-Logic II), and Smart Volume Normalization processing to your digital music files
Accessories 1 x Optical S/PDIF adaptor cable
1 x Stereo Vertical Array Microphone

All this is bundled into a package that could be mistaken for a salt or pepper shaker. Let’s take a quick look at the packaging.

The front of the box shows a color shot of the U1 and lists all the Dolby effects along with an overview of the features, while the bottom has the serial number, part number, part name and bar codes for inventory control.

The rear of the box lists more features in twelve languages. Saves on packaging costs.

On one side, the package lists the driver’s features, bundled goodies and system requirements. While the other outlines the the hard specs, the audio pr0n if you will, which I’ve shown in the table. The tape on the flap illustrates that the flaps are a royal pain in the old posterior to open. I ripped the flap when I was doing a cursory examination of the U1 to make certain UPS hadn’t killed it.

Opening the box flap (did I neglect to mention there being a flap on the front of the box? Shame on me) shows more of the same specs listed elsewhere on the box along with showing the various colors the U1 comes in (blue, red, yellow, black, polished and white) and a window shows you the color of the unit contained within the box.

Opening the box reveals that the U1 is bundled away pretty securely, at least it should survive some less than TLC during shipping.

Popping open the flap not over the U1 reveals the array mic, the baggie with the SPDIF adapter and the (very short) cable for the U1. ASUS was kind enough to supply a hook/loop tie wrap for the cable on the U1, a nice touch if you’re planning to haul it around in your laptop bag. I wish they’d been as forward thinking for the mic cable though.

Lifting the flap over the U1 reveals it in all it’s salt shaker glory. The upper part of the U1 is the volume control slash mute button. To increase the volume a clockwise rotation is all it takes, Conversely turning it counter clockwise drops the volume while pushing the top down mutes the sound. Pretty handy, no pun intended.

Under the U1 is a hidden compartment containing the quick start guide, driver CD and a demo DVD. The driver CD also features a utility called ASUS PMP lite and a text owner’s manual. PMP lite is a utility for ripping audio (which I didn’t play with, I’m content with WMP 10) and will only function when the U1 is connected to your system.

Here’s a shot of the U1 in all it’s glory with the toslink SPDIF adapter stuffed into the audio output. Oops, it’s in the input. Sadly, the input only serves double duty, it’s a mic input and line level input but it doesn’t do SPDIF duties. The output jack is the only one gifted with SPDIF capabilities. I imagine that SPDIF input would’ve increased the complexity of the unit past the point of being able to fit into the svelte profile ASUS used. Yes, it would be nice but those are the breaks.

Spinning the U1 around we see that there’s a Dolby headphone logo imprinted into the back above the cable. Yes, it’s imprinted into the unit as are all the legends on the U1, they’re not merely silk screened on. This is on top of the fact that the U1 is made with a solid metal shell and has a non-skid rubber foot.

The metal shell will help insure that no stray interference messes with the quality of your audio and that it will survive a bit of rough handling. I say bit because the potentiometer used allows the top to wobble around a bit which doesn’t give it the most sturdy feel.

Here’s look inside the U1. I wanted to test it out fully before attempting to get it apart just on the off chance I killed it in the process, that’s why it’s sitting on my mouse pad rather than on the same backdrop I used for the rest of the shots.

If you look towards the top of the shot you’ll notice a metal mesh, it runs under the PCB, where the plastic base is, completing the faraday cage thereby making a complete shield. The caps are United Chemicon KMG series which is good and the OPAMP is a Texas Instruments part, Burr-Brown possibly? Given the SN/R numbers it’s a lower end part if it is Burr-Brown.

The potentiometer has a very slight detent action to it so that you get some feedback when the top is rotated. Pushing down on the top engages the mute function. There are also four tri-color LED’s on the PCB. They list two colors, blue while in use and red with the mute on but while I was installing the drivers, the LED’s lit violet before the drivers were fully installed. So, if you find that your U1 isn’t working look at the indicator on the knob, if it’s violet, you’ve gaffed the driver install somehow.

Here’s a closer look at the array mic, it’s on a short flexible stalk. The array mic is a passive noise reducing design that drops ambient background noise by 15db while giving up to 60db boost to sources in front of the mic. ASUS claims that it’s even capable of driving voice recognition software, a nice bonus if you’re not into headsets.

Here’s a quick look at the bundled disks, the DVD disk has various scenes on it encoded with different audio enhancements versus plain two channel audio so you can get and apples to oranges comparison of what the enhancements bring to the table without having to switch through them. I’ll go into the enhancements in a bit.

The quick start guide is pretty simple and gives you the needed info on everything from driver installation to hooking up various devices to your U1.

No mention is ever made about the violet light, I just figured that bit out on my own during the driver install, I’ll recount that in a bit.

As you can see, you can hook audio devices to the mic input, just bear in mind that you’ll be using an analog signal path. The sound won’t be as sharp as if you ripped the audio to your PC or played it directly on your PC (in the case of CD players).

The SPDIF is a nice concept but there are a few caveats. The PC will need to be close to the decoder unless you want to use an expensive extended length toslink cable or you use a USB extension cable to place the U1 closer to the decoder. Not a major deal for someone using this little gem to encode Dolby for an HTPC rather than a more expensive discrete audio card but for users wanting to hook up their notebook to a home theater receiver it’s something to ponder.

Sound Driver

When you first fire up the drivers (after you finally get them installed) you’re greeted by this slick user interface. Clicking the menu button causes the spectrum analyzer to slide up like this:

Revealing the various buttons that allow you to interact with the drivers. On the main you have the sample rate (fixed at 48KHz) analog out, SPDIF out on or off checkbox and 7.1 virtual speaker shifter toggle and Dolby virtual speaker toggle. If you choose headphones in the analog out, the Dolby virtual speaker toggle is replaced by the Dolby headphone toggle.

Punching the mixer button brings up the mixer (big surprise, huh?) with buttons to choose between record and playback.

Punching up the effect button brings up the digital soundfields along with the EQ. Oddly, if you’re using any of the DSP modes (below the volume knob) and you punch in any of the EQ modes, it turns the DSP mode off and sets it to "User Defined". This simply turns the button’s color from lit green to being dimmed.

Since I’ve brought up the volume knob, I’ll touch upon the fact that it doesn’t make an appearance until you hit the menu button. In fact everything to the right of the spectrum analyzer isn’t there until then. Hitting the menu button makes it all magically appear.

The SVN button is for keeping volume levels at a constant level. It compresses loud sounds and boosts soft sounds which is nice for movie listening when you find yourself scrambling for the volume knob constantly. For music listening I found that it was less than desirable as it choked the music back too much and muddied transient responses.

I know I’m skipping over the digital soundfields but that’s because I find them largely useless. They’re too strong to make extended listening worthwhile, they end up being a detractor from the experience. Until ASUS decides to put a mix slider in place they’ll continue to be more of a distraction than a benefit.

The karaoke button brings up the standard gimmicks. Voice cancellation, pitch shifting, mic echo and magic voice. The voice cancellation works to varying degrees of success depending upon how the music is mastered. Pitch shifting ends up making the music sound odd but if you’re like me, you’ll be murdering the music so bad that how the background music sounds will be the least of your worries.

The mic echo works pretty well allowing you to go from a fairly dry mix to a wet mix that’s just dripping with reverb. Magic voice is the least useful thing there, making you sound like anything from a chipmunk to lurch. Good for laughs but that’s about it.

The array mic button brings up the toggle to turn the array mic on or off. Pretty simple.

Now that we’ve waded through the drivers I’m going to discuss the issues I had installing them. ASUS says to hook up the U1 and cancel the new hardware wizard and instead launch the software to install the driver from the CD. Doing so brought up the installshield wizard which went about installing the drivers.

Everything hums merrily along until the drivers start looking for the hardware and then things go pear shaped. Windows disallows the install since the driver is unsigned, the driver fails to install and you get a message telling you to reboot the PC and try again. Upon rebooting and trying again the same thing happens.

I ended up starting the found new hardware wizard, telling it to find the drivers automatically and okay’ing the unsigned drivers every time I got the warning. Wait, it’s not over. After that I had to reboot the PC, start the installshield wizard and go through the driver install from there before the violet LED’s finally turned blue and the drivers were recognizing the U1.

I don’t blame the drivers as much as I do Windows. After a slew of updates, Windows has become so paranoid about unsigned drivers that native drivers in Windows cause problems with everything from USB mice and keyboards to plug and play monitors. Do you know how annoying it is to hook your mouse up to a different USB port than the one it was hooked to when the OS was loaded to only barf up and unsigned driver alert and you end up with no mouse? If so then you know what I’m talking about.

Anyway, after fighting with Windows, I got the driver installed and took the U1 for a spin (again, no pun intended). On to testing!

Testing, Final Thoughts

Music Listening

For my listening tests I listened to a large variety of music ranging from Alanis Morissette to The Bloodhound Gang to White Zombie. In Hi-Fi mode (no EQ, two channel speakers, no DSP) the sound is fantastic. The bass is tight and accurate with good low frequency response. No loose booming or muddiness.

The mids are crisp but not harsh. Hard to pull off with digital music as it tends to be unforgiving in the midrange but the U1 pulls it off quite well. Saturated guitars drip with distortion but none is added by the signal chain. Mind you this was in speaker mode. I found that in headphone mode that there was some grain in the upper midrange when you pushed the U1 too hard.

When the U1 wasn’t supplying the power to push a set of headphones and instead was feeding a preamp stage, the sound was really good even at high volumes. If you’re using headphones with a high sensitivity I don’t think you’ll ever push the U1 to the point of clipping but if you’re using a middling efficient set you might think about investing in a good headphone amp.

To tell you how well the U1 reproduces source material I was listening to "A Lapdance Is So Much Better When the Stripper Is Crying" by The Bloodhound Gang and I noticed a hum. It sounded like the kind of 60 cycle hum from an open circuit but it was quite a bit lower than the music. I sat there thinking "Oh snap, there’s a problem somewhere" and paused the song preparing to sort through the issue and the hum went away. Lo and behold the hum was from the song. This is something I’ve never noticed before. To be fair I generally listen to that song in the car or on my MP3 player, I haven’t listened to it on my PC in years but I was still taken aback that I’d never noticed it before.

Movie Listening

For the movie listening phase I gave "Fantastic Four: Rise of the Silver Surfer" the nod. For this test I tried it both with Dolby headphone and with Dolby virtual speaker. I have to say I’m not as impressed with the Dolby effects as I was with the music listening. Dolby headphone makes it sound like someone put tubes over your ears at most points and at some points it sounds like you’ve stuck your head into a concrete tube about 15" in diameter.

There’s no real "surround like" sound, just some odd reverb added to the source material. The Dolby virtual speaker was a bit better but not much. At some points I’d find myself hearing the phantom speakers but most times it was just a bunch of added delay that just screwed up the sound. As a comparison, I switched back to the X-Fi Prelude and enabled the Dolby virtual speaker effect in Power DVD and the effect was much closer to a real surround soundfield without the added distraction of a bunch of unnecessary reverb.

Unfortunately, I can’t do any Right Mark Audio Analyzer testing since there’s no way of looping the signal back so we won’t go there and instead we’ll move along to the scoring and summary.

The Xonar U1 is a decent little device that comes really close to being a must have piece of hardware but misses the mark on a couple of points. The play in the potentiometer is disturbing as it makes it feel a bit flimsy but the acid test will be six months of being lumped around in a laptop bag.

The Dolby effects are a bit too overblown for my tastes, I think that they should be tuned down a good bit but they’re nothing that some tweaking can’t fix. On the other hand, the music listening was top notch and if music is what you’re into you really will be hard pressed to find a better setup to radically improve upon the onboard sound found in most of todays laptops.

All told I’d say that whether the U1 is your cup of tea will depend largely upon what you’re looking to achieve. If you watch a lot of movies I can’t say if you’ll be turned on by the U1 but if you’re heavily into music you definitely need to give it a listen. That said, I’m awarding the Xonar U1 a 7/10 and running for cover before someone starts shooting at me.

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