Using the included USB pigtail, listeners can plug in a portable USB drive or MP3 player for complete access to the file structure. Compatible file formats include DRM-free MP3, AAC, and WMA.
In a nice tip of the hat to iPod users, Alpine has included a short, black dock connector cable with the X305, which looks cleaner and keeps us from having to carry our stock white cable back and forth.
New in the X305 is full "Works with iPhone" compatibility, so no longer will you get a nag screen when connecting your iPhone 3G. Additionally, the X305 will also charge your iPhone while you listen, something that the X100 didn't do.
While the iDA-X305's feature set is essentially limited to radio and digital audio playback, it is capable of being extended and expanded with Alpine's line of add-on modules. We already mentioned the KCE-400BT, but the X305 is also compatible with Alpine's TUA-HD550 HD Radio tuner with iTunes tagging functionality.
The internal amplification receives a 5-watt per channel boost from the X100 to the X305. However, while power is now rated at a peak output of 50 watts by four-channels, average power output remains at 18 watts per channel.
The character of the audio can be tweaked with a two-band (bass/treble) equalizer with a loudness function. Those who need more control can add the IMPRINT audio processor for an additional charge to custom tune the audio to their particular vehicle.
Additional power can be had by way of the upcoming headunit power pack, which boosts average power to 50 watts per channel, with an unstated max, or by adding external amplifiers using any of the three 5-volt preamp outputs (including a dedicated subwoofer output, with its own gain control).
Everything that we liked about the X100 is back and better than ever in the iDA-X305, so our recommendation of this receiver for people with large digital audio collections is a no-brainer. We also like the extendability of the X305 through Alpine's collection of add-on modules and the freedom it gives us to build our cabin tech experience one piece at a time.
However, while many users have successfully made the jump to a completely device-based approach to their music collections, many more still depend on physical media. If you can't break your addiction to CDs, perhaps this isn't the receiver for you.