more info on this. looks like the concert in the new A4 has an SD card slot and can link to the AMI interface:
The next radios up the scale are the concert and the symphony units. Both are from the new Audi audio generation and have a 6.5-inch colour display screen. Their controls are in accordance with Audis much praised MMI logic, and use a rotary pushbutton and large switches ideally positioned for intuitive operation.
An optional lifestyle feature for the concert and symphony radios looks well ahead into the future of portable music: the Audi music interface (AMI). For many people, the ability to carry a library of music around with them, often stored in an iPod, and use it everywhere has become a firm element in their lives.
The AMI interface is capable of linking to the customers iPod and allowing all its controls to be used. The radio display then displays the players menu structure with all its replay lists and additional information; operation is from the radio or the multifunctional steering wheel, another optional extra.
The AMI links with a fourth-generation iPod; by means of a separate adapter cable, any other audio player with a USB 2.0 interface can also be connected. Its data will then be played via the cars audio system, though no control facility is available in this case. Audi has designed the AMI software as modular elements individual drivers are included in the memory for communication with the players and to enable their protocols to be read. If a new player comes on to the market, its driver can be installed quickly and easily as an update.
Double tuner: two aerials, two receivers
The concert and symphony radios contain a double tuner: a digital processor takes its signals from two aerials after pre-processing by the two tuners. One of the tuners plays the music, so to speak, while the other searches in a regular cycle through all the available stations in the background, in case a better signal can be received. This technology suppresses what is known as multipath interference, as caused for instance by signal reflections from buildings or in the mountains. It calls even weak stations down from the ether, since the two reception paths can be combined in such a way that the two aerials perform a direction-finding function.
Quite apart from the AMI interface and the double tuner, both Audi radios are genuine all-rounders. They have an SD card reader (SDM = Secure Digital Memory) for audio files and a CD drive; both of these can also play music in the mp3 and wma formats.
A six-disc CD changer is integrated into the symphony radio. As with the chorus radio, the 4 x 20 watt amplifier supplies four channels and eight speakers. The extended CAR menu control facilities are a further welcome feature.
A highlight in the midsize class is the option of digital audio broadcasting (DAB) on the concert and symphony radios and on the navigation systems. Digital VHF signals are superior to the analogue standard in their dynamic range, clarity and spatial quality. DAB is in widespread use in many European countries, with almost complete coverage in Germany, Great Britain and Belgium. Audi DAB tuners compute the stereo signal by way of a signal processor, and prepare additional radio-text data in parallel
