Review: Engineered Audio Aurius

We’ve covered a number of ways to get your music from your computer to your home stereo, ranging from Apple’s $129 AirPort Express to wireless players such as Slim Device’s $300 Squeezebox to higher-end systems such as Sonos’ Digital Music System. But most of these products are designed to get your music across your house . If your goal is instead to just get your music across your room , or just into the next room, these systems are often overkill. A long cable might work, but what you really need is something in between.

Engineered Audio’s $40 Aurius may be just the solution. Like the myriad FM transmitters available for the iPod, the Aurius takes your computer’s audio and broadcasts it over the FM frequency of your choice, where it can be picked up by your home stereo, portable radio, or any other FM tuner (even FM radio headphones). It’s a unique and inexpensive approach, and the Aurius performs well—within the limitations inherent to FM transmitters, that is (more on that below).

The Hardware

The Aurius hardware consists of a small, white, transmitter just under 3.5 inches long, 2 inches wide, and 1 inch high, and weighing just a few ounces—small and light enough to throw in your bag for use with a laptop. You simply connect the Aurius box to any USB port on your computer via the included USB cable—the transmitter gets its power from the USB port. (Engineered Audio recommends against connecting the Aurius to a USB hub, citing the low latency and high bandwidth requirements of USB audio; I can confirm this, as I experienced much more static during playback when the transmitter was connected to a hub.)

There are no controls on the Aurius, as you choose your FM broadcast frequency on your computer using the included software (discussed below). However, the transmitter does provide a line-level audio output minijack for those times when you don’t want to broadcast your audio via FM—you can connect your computer speakers, or even a nearby stereo, directly to the Aurius. The only drawback to this feature is that the transmitter continues to broadcast when using the Aurius in this way. (This is actually a consequence of a broader design decision, discussed in the next section.)

The Software

As mentioned above, you control the Aurius via software on your computer. The first step is to install the Aurius drivers. On a Mac, you double-click the AuriusDriver.pkg Installer package to perform the installation, which requires a restart. If you’re running Windows, you unzip the Aurius application and driver folder to your hard drive, then plug the transmitter into a USB port. When Windows’ New Hardware Wizard appears, you browse to the folder containing the drivers. You can then use the Aurius right away—no restart required. In either case, the process is fairly painless and your computer should automatically switch to the Aurius for audio output.

You then use the Aurius application to choose the FM frequency over which you want to transmit, from 88.1 to 107.9 MHz (in odd-decimal intervals: .1, .3, .5, .7, .9). In both the Mac and Windows versions of the Aurius software, a large display shows the current broadcast frequency; you move a slider left or right to change the frequency. (The change happens “live,” just as if you were tuning a radio.) You simply synchronize your radio and the Aurius frequencies and voila—your computer’s audio is broadcast to your radio.

The Windows version of the Aurius software also provides arrows at each end of the frequency slider which decrease or increase the transmission frequency one “notch.” This feature is quite useful for fine-tuning the frequency (e.g., from 99.7 to 99.9); dragging the slider is more useful for making big jumps (e.g., from 89.7 up to 102.5). Unfortunately, this feature is missing from the Mac version. On the other hand, the Mac version allows you to—in theory—use the arrow keys on your keyboard to fine-tune the transmission frequency. Unfortunately, in the version of the Aurius software I tested (1.1a), the up and right arrows increased the frequency .8, whereas the down and left arrows decreased the frequency 1.0, making using these keys an exercise in mathematics: How do you increase the frequency from 99.9 to 102.5? (Answer: 7 ups, 3 downs.) Granted, this is a minor issue, but since the Mac version is missing both arrow buttons and functional arrow key tuning, I found fine-tuning to be more of a hassle than it should be. (We’ve reported this issue to the developer and will update this review with their reply.) I’d like to see all of these feature work consistently on both platforms, as well as the ability to save presets for commonly used frequencies. [ Update, 5/5/2005: We received word from Engineered Audio that a “complete overhaul” of the Aurius software is in the works that addresses this issue. Once the new version of the software is released, we’ll post an update to this review. ]

Once you’ve chosen your broadcast frequency, the Aurius software doesn’t even need to be running—the transmitter continues to broadcast using the frequency you’ve chosen. (In fact, the only way to prevent it from broadcasting is to unplug it—even routing your computer’s audio to another output source doesn’t stop transmission. I would have appreciated the ability to turn the Aurius transmitter off, either via software or hardware.) That being said, the software does provide two additional settings that can be useful: A mute control lets you toggle mute mode on and off, and the stereo/mono opton lets you switch to mono mode if stereo mode produces too much static. (As with standard radio, mono mode also lets you broadcast over longer distances with less interference.) Unfortunately, the Aurius software for Windows has a bug that made us keep it running full-time: It reverts to 107.9 each time you launch it—it doesn’t remember the frequency you last used. It also defaults to “muted” mode when launched. (The Mac software doesn’t exhibit these glitches.) [ Note: See the note in the previous paragraph about upcoming updates to the Aurius software. ]

Finally, one other issue worth mentioning is that the Aurius’ ability to broadcast your computer’s audio is an all or nothing thing—you can’t send your iTunes music to the Aurius for broadcast to your home stereo while keeping your alerts and other sounds playing through your computer’s local speakers. However, there are third-party workarounds for this limitation. For example, Mac owners can use Rogue Amoeba’s Detour to decide which applications send audio to which output device.

Performance

As we’ve noted in our reviews of FM transmitters for the iPod, FM transmission by its very nature has drawbacks, and the Aurius doesn’t perform miracles. The greatest problem with FM modulation is that if you’re in an area where the FM spectrum is saturated with stations, it may be tough to find a frequency clear enough for use. And even if you do find a clear frequency, the audio quality will never be as good as a direct connection (i.e., a cable) due to limitations of FM itself. Finally, when broadcasting via radio frequencies, if your source goes silent, your radio will often produce the same sort of background noise you hear when your favorite radio station goes silent. So, for example, if you’re listening to iTunes via the Aurius, and your playlist ends, you’ll likely hear some amount of buzz or static. This makes the Aurius (or any FM transmitter, for that matter) better suited for listening to music than for broadcasting a computer’s audio full-time.

I point these issues out not to criticize the Aurius specifically, but rather to offer realistic expectations. But given that context, in my testing in the heart of Silicon Vally—where there aren’t many free FM frequencies—the Aurius performed admirably. Although it was still common to hear a bit of static during periods of silence—again, I haven’t used an FM transmitter yet that doesn’t exhibit this behavior—for broadcasting music to a stereo the Aurius worked very well, providing sound quality comparable to or better than standard FM radio. For example, using Engineered Audio’s recommended volume levels (iTunes at 50%), I heard no distortion or dropouts when using the Aurius in the same room as a stereo with an FM tuner.

In terms of range, I was pleasantly surprised by the Aurius’s broadcasting capabilities. Engineered Audio advertises range of 30-50 feet, which I’m assuming to mean unobstructed range. Yet using my favorite FM radio, the Tivoli Audio iPAL, I was able to clearly receive the signal from a Mac mini playing music in iTunes halfway across the house, through several walls. I also tested a few “lesser” tuners: An older JVC receiver with a simple wire antenna fared just as well from approximately 25 feet away through several walls, but an inexpensive “bookshelf” system had trouble receiving a static-free signal at the same location. (It had no problems at shorter distances or with fewer walls in between.) Of course, results will vary from house to house, and depending on the FM frequency saturation in your area, but I give the Aurius two thumbs up for range and sound quality, especially compared to some of the FM transmitters for iPods that we’ve tested.

The Lowdown

The Aurius isn’t perfect: Its software has a number of minor glitches that I’d like to see addressed (the Windows version’s inclination to reset the broadcast frequency each time you launch it being the most annoying). But these are interface issues in a product that doesn’t require much of an interface, so it’s hard to knock the Aurius too hard for them. Overall, it’s a solid product that lets you broadcast your computer’s audio, in stereo, across the room or halfway across the house for a fraction of the price of other wireless solutions. For those with modest needs, it’s a bargain in comparison. And the fact that it’s so small and lightweight means it can easily fit in your laptop bag for use during presentations or in your hotel room.