Smaller than a computer mouse, the Creative Xmod packs some surprising sonic powers inside its sleek white shell. The Xmod is a combination audio interface and enhancer. When you plug it into your computer's USB port, the Xmod becomes an external soundcard, taking over the audio input and output duties and adding a handy volume knob. Pressing the knob even mutes the audio. Flip the Crystalizer switch and the Xmod does some fancy digital signal processing to "restore" the audio information hacked away by lossy compression schemes such as MP3. (Creative enthusiastically describes the result as sounding "better than CDs.") A 3D switch creates a virtual surround effect on headphones or stereo speakers.
A couple of months ago, I got to review an Xmod and I loved it. So when I had to return the review unit, I went out and bought one with my own money. That's when I really started to go wild. In this article, I'll share some of the unexpected ways I've found to pump up digital audio with the Xmod.
The Xmod's enhancement effects are derived from Creative's X-Fi sound cards. Creative's engineers did a lot of modeling and mathematics and figured out how to localize sounds by using the physics of the human ear, the shape of the human head, and advanced digital signal processing. By employing delays, HRTFs, and other signal processing techniques, they turned the two real speakers of a pair of headphones into simulated nine-speaker surround sound.
The results sound impressive. You tell your computer to treat the Xmod as a Dolby Digital 5.1 output device, plug in your headphones, and the audio surrounds you using virtual speakers as the device decodes six-channel AC3 audio streams from your DVD. The rumbles, vrooms, and kabooms fly from left to right, from front to back, and sometimes they travel right through your head. Groovy stuff, even without chemicals.
Of course, Creative isn't the only company to deliver virtualized sound. You can buy the same sort of signal processing from other vendors such as Bose, Dolby, and SRS. The Creative Xmod, though, gives it to you in a compact, affordable device. And it works on both headphones and speakers.
Figure 1: Switches on either side of the Creative Xmod allow you to enable or disable the X-Fi Crystalizer and the X-Fi CMSS-3D effects. The line input is at front left; the headphone output is on the right. Around the back are the USB port and line output.
Think about that for a second. The mathematics of headphone and speaker delivery are quite distinct. When delivering sound to headphones, you deal with two isolated signals. You feed one signal to the left ear, another to the right. You don't have to worry about sounds traveling through your head to get all mixed up on the other side.
Working with speakers is different. Sounds cross from left to right and right to left, because there's no physical barrier between them. So the mathematics gets trickier because you've got to build an ideal listening environment for the person sitting in the middle while the crossed-over sounds have to either strengthen or cancel each other out.
The Xmod provides both kinds of outputs—speakers and headphones—automatically switching effects when you plug into the headphone jack.
But that's not all the Xmod can do. It also offers a feature called the Crystalizer. The Crystalizer restores missing frequencies and dynamic range to compressed sound. This processing produces deeper bass sounds, clearer voices, and an overall better defined signal—or at least it does for clean, well-recorded data. When dealing with noisy source material (such as homemade podcasts), the Crystalizer accentuates the high-frequency noise, making the podcasts really hard to listen to. But for clean sound, the Crystalizer is indeed sparkly.
The threat of enhanced noise is just one reason to be judicious when enabling the Xmod effects. Fortunately, the Creative folk have built two switches into the device (Figure 1). One turns the Crystalizer on or off, the other enables and disables the 3D effects. You can experiment as you listen; there are no delays when changing settings as processing is all done in real time.
Tip: It's rare these days to find a computer without a microphone jack, but they do exist. My ancient 733MHz G4 Macintosh doesn't have one but it does have a USB port. Some underpowered laptops, like certain Dells, can start sputtering their audio when you begin moving the mouse. So it was a nice surprise to discover that I could plug a mic into my Xmod, fire up Skype, and basically treat the little white box as the external mic jack that I've always wanted. In other words, an Xmod can function as a compact, portable audio interface. Although the manual says, "Monitoring of recordings is not available. You can only check your recording afterwards," I've never encountered any problems monitoring my Xmod during Skype chats or for any other microphone or line-in use.
Have you ever wanted to go up to a designer and smack him on the head, Three Stooges-like, for his design blunders? The guy who designed the default effect levels for the Xmod probably deserves one of those smacks and here's why. To change the levels, you need to use a "secret button." As Figure 2 shows, this button is the entire top half of the Xmod. Press it and you'll feel a click.
Figure 2: The upper half of the Xmod acts as a secret settings button, allowing you to set the intensity of each effect rather than just switch the effect on or off.
Here's how it works: normally the large silver knob in the center of the unit adjusts playback volume. Turn it clockwise and you increase your system's volume; go counterclockwise and you decrease it. Click the knob and you toggle Mute. (When sound is muted, the third light from the top of the unit turns red.)
To adjust the intensity of the Crystalizer effect, double-click the secret button. The second and third indicator lights switch off and the blue light that usually indicates whether the Crystalizer is enabled or disabled begins to blink. A fast blink tells you the Crystalizer is cranked up high. A slow blink tells you the effect is diminished. Adjust the knob, turning counterclockwise to decrease the effect or clockwise to increase it. The light changes its blink rate accordingly.
There are no numbers. There are no blinks-per-second codes (at least not as far as I could figure out). It's all subjective. Faster means more Crystalization, slower means less. And if you wait more than about five seconds without touching anything, the entire Xmod exits the settings mode and returns you to normal playback mode.
To adjust the 3D effect, double-click the secret button (the Crystalizer light begins to blink) and then click once more. The blinking indicator moves to the X-Fi CMSS 3D light. Again, adjust the knob counterclockwise (less effect) or clockwise (more effect) and watch the blink rate increase or decrease. To finish your settings, click the secret button one last time or just wait five seconds. The Xmod leaves the setting mode.
It's a half-assed, clunky way to change your settings, but it does allow users to dial back on the Crystalization, which can be distracting at its most intense setting. I prefer to leave the 3D effects full-on all the time.