Originally Posted by Technic
Use a LOC -the XD400/4 accepts up to 5.6V peak. Your OEM HU outputs 8V peak.
Eh, even so, with the sensitivity cranked all the way down, the speaker volume will be unbearably loud before you hit a level potentially damaging to the amp. The only real reason to use a level shifter is to recover some of the volume control resolution on the head unit, but I find there to be plenty of notches to play with as is.
Originally Posted by ctuna
2010's and some early 2011's got the base system.
The worldwide base system with no amp .
There were a lot of people pretty upset about this.
BMW reinstated the Hi Fi as base system around sept of 2010 in 2011 builds
but still a month or two of base system slipped through .
They are easily identifiable by the lack of tweeters in the front doors.