There is no direct analogue to Boston Acoustics’ i-DS3 Plus ($499) speaker system for iPods and iPhones. It is, in short, the more powerful and impressive successor to the i-DS2, an iPod-only system we reviewed and liked last year, and the Horizon Duo-i, an even more impressive unit that we reviewed before that. i-DS3 Plus continues i-DS2’s minimalist styling and straightforward feature set, adding iPhone interference shielding and considerable power under the hood. It is, in short, an impressive little 2.1-channel audio system with one especially novel feature and only three caveats: limited user adjustability, questions about its future video expandability, and a high but not offensive entry price.
What i-DS3 Plus offers users is a mirror of the iPod and iPhone sales pitch: an extremely clean industrial design that hides smart internal components. The base of the system is a unified dock, amplifier, and speaker system that is roughly 15.5 inches wide, up from 12.75 in i-DS2, 6 inches deep versus i-DS2’s 5.75”, and roughly the same 5.5 inches in height. These differences mightn’t be enough for the average observer to notice without seeing the two systems side by side in person, but they’re apparent when placed next to each other; i-DS3 Plus’s body is actually more streamlined than i-DS2’s, which borrowed speaker chamber curves from Horizon Duo-i; they’re all gone now in favor of a cleaner, simpler shape. As with i-DS2, you can choose from glossy black or white as the unit’s color, and also purchase one of nine replacement $20 metal grilles to customize its front color from the original black or white matte surface.
i-DS3 Plus’s main unit size change is attributable to several major differences in its internal hardware: Boston Acoustics has shifted from a surprisingly competent two-speaker design to an even better four-driver design, increased the amplifier power, and added a 2.4GHz wireless transmitter. This transmitter can be switched between four 2.4GHz frequencies to avoid interference with your home wireless phones and network—we had no issues using it in our test environment on setting 1—and communicates with a wireless subwoofer unit that’s included in the box.
Measuring roughly 11.5” square at its base, the i-DS3 Plus subwoofer houses a 6” dedicated bass driver that fires downwards, providing some sub-sonic vibration, and a wireless receiver that communicates with the system’s dock and transmitter.
Boston Acoustics has kept the subwoofer simple: the back has a power switch, a volume dial, a four-channel wireless frequency switch, and a port for the power cord. There’s no need or ability to connect a wire between the subwoofer and main speaker dock; the subwoofer can be placed anywhere in a room, unobtrusively adding deep bass (35Hz to 150Hz) to the system. The subwoofer comes in the same glossy plastic color as the main unit, and has no color-swappable parts.
When Boston moved from the Duo-i over to the i-DS2, it devolved what was a cool but complex integrated control interface over to a simple three-button design: plus and minus buttons for volume, and a glowing blue button for power. i-DS3 adds a fourth button to this array, glowing red to indicate a wireless connection with the subwoofer, while keeping all other controls on an included remote control. Still based on Infrared technology, the new remote has the same seven play/pause, power, volume, track, and mute buttons as its predecessor, but adds four more: one to activate the wireless subwoofer, shuffle and repeat controls, and finally a video-out button. The video-out button only needs to be pressed once to keep the unit thereafter outputting video to its rear-mounted composite and S-Video ports; if it’s not pressed, the system will seem incapable of passing through video from the latest iPods and iPhones. Thankfully, it all works as expected. All that’s missing from i-DS2 in functionality is the prior unit’s rear-mounted USB port; the larger i-DS3 Plus wasn’t designed to sit near a computer.
Sonically, it would be hard to overstate the difference between the i-DS2 and i-DS3 Plus. While Boston Acoustics did a good job of exploiting the two 3.5” drivers in the i-DS2, four well-tuned drivers are almost always necessary to provide truly great audio reproduction, and the i-DS3 has them: it adds twin 1/2” tweeters to the base unit, then the 6” driver in the subwoofer, collectively delivering 2.1-channel audio that’s worthy of a mini home theater.
Because i-DS3 Plus has more drivers in a line, plus less need to push only two speakers to reproduce the full audio spectrum, the main unit alone creates sound that has more treble and more midrange detail than the i-DS2, plus noticeably improved staging. Collectively, these changes help you hear sounds that wouldn’t have been evident in the prior system, making music “pop” and appear to come from beyond the edges of the enclosure when heard through the main unit; i-DS2 sounds comparatively flat, and constrained to the smaller size of its casing. i-DS3 Plus’s 100-Watt total amplification also enables it to scream if you want to push it to its highest volume levels.
One non-trivial change to the i-DS3 Plus’s main speakers, however, is that they now rely upon the subwoofer to handle most of the low-end sound that i-DS2 could produce on its own, as well as even deeper frequencies that neither the i-DS2 nor comparably sized systems such as Bose’s SoundDock could produce. If the subwoofer’s turned off, i-DS3 Plus sounds bass-deficient, so you’re almost always going to want to use both parts together. When it’s on, i-DS3 Plus is capable of generating such low tones—and loud ones—that you can watch movies on your iPod or iPhone and feel the floor shaking with the low, bassy clomps of feet or rumbles of engines. This is one of the most powerful little iPod audio systems we’ve tested over the years, and definitely the most powerful unit yet to boast iPhone shielding. Notably, though the system is silent when near iPhones in 3G mode, it still is subject to low-volume EDGE interference from original iPhones and 3G models operating in EDGE mode, a common issue with speakers that are “Works With iPhone” certified, but only for iPhone 3G models.
The only complaints we had with the i-DS3 Plus were three in number. First, like the i-DS2 but unlike the earlier Duo-i, i-DS3 Plus lacks integrated equalization controls—there’s a bass volume knob on the subwoofer, but no unified digital treble and bass adjustment system to impact levels on both the main and sub units at the same time.