This is common with BMW stock sound-systems. Something to do with taking an audio-feed from the rear speakers causes the entire sound-system to stop audio altogether. This happens in E39 and E46 models, but they can be reset straightaway with the ignition. The E60 and other iDrive models need a 16-minute cool down before audio can be restarted and this just won't do.
The problem did not occur in my E39 using an Alpine V12 1kW amp, only with a cheaper 'Toxic Audio' 1kW amp I was given at some point. This has its own volume control and the Alpine is just too loud, but with the long cut-out in the E60 I may simply have to revert back to it and turn bass all the way down on the head-unit. Having said that, there's no guarantee the Alpine will not still cut out audio and I have now found similar cases from people who have bought brand-new, good quality amps, so it looks like that rules out a fault with the Toxic. Worse still, my stereo suffered the audio cut out this week while the amp was plugged in to the speakers but not even turned on [no remote-signal], so this would back up my original fears that the cut-out is to do with too much current being drawn through the rear speaker cables, causing the head-unit to shut down all audio until the system is reset [fully powered-off and back on].
Here is a thread about it on
bmw5.co.uk , I cannot say if the power of the amp versus the subs has anything to do with it though -
http://forum.bmw5.co.uk/topic/83362-new-sub-woofer-issues-with-audio-cutting-out/
** UPDATE:
After fitting the Alpine V12 amp I have not had any sound cut off issues, just as it was in the E39, but it is still way too loud and overpowering the system, even with bass turned all the way down on the head-unit / iDrive.
To finally get this Alpine amp in balance with the stock system I've bought a crossover-box off eBay, which is a slight extra power-drain, but at least it has a Gain control for each channel so I can turn the subs down and the bass on the stock speakers back to normal. It also cuts out the high frequencies and lets only the low ones through for the subs, though I'm not sure if this will do a great deal for sound quality. I cover fitting that in
THIS POST.
