[jin]

Hey guys my underseat mids are not working. I pulled them out and tested them - they are fine. So means the L7 amp is faulty.

Is there a DIY to fix the amp? If not possible to fix then what aftermarket amp/processor is recommended? I would rather not replace with another L7.

[ptpending]

you can see three or four amplifier chip radiators on the sides of the amplifier, if you have skills to trace dead and replace it - you can fix it, otherwise it will cheaper to get another amplifier from ebay

[ctuna]

Repair
http://www.bmwradiorepair.com/?gclid...FccbQgodIEn0Cg
http://beckerautosound.com/
http://www.bmwgm5.com/Logic7_6941681.htm

If you want to upgrade its quite convoluted for L7 due to the proprietary
fiber optic interface between the amp and Head Unit/idrive.

You either have to recode the output to Hi Fi or buy a mobridge preamp(da2 or da3)
that will convert the output to analog signals. Then buy a multi channel amp
something like the Helix 82dsp or 6dsp is popular now. At least the front speakers doors and underseats should be upgraded at the same time.

See the Audio Build thread sticky at the top of the page in forum page 1.

BMW stereo types
http://www.e90post.com/forums/showthread.php?t=352586
http://www.e90post.com/forums/attach...2&d=1266451970
http://www.e90post.com/forums/attach...2&d=1260829447
http://www.e90post.com/forums/showthread.php?t=343673
http://www.e90post.com/forums/showthread.php?t=138949
http://www.e90post.com/forums/attach...1&d=1209780605
http://www.e90post.com/forums/showthread.php?t=641323
http://bmwcoders.com/forum/3-er-8/bm...1-e92-e93-291/
http://www.e90post.com/forums/attach...1&d=1209780865
electical e90 pdf
http://www.google.com/url?sa=t&rct=j...,d.cGU&cad=rja
http://www.google.com/url?sa=t&rct=j...85464276,d.cGU
http://www.google.com/url?sa=t&rct=j...85464276,d.cGU
http://www.musicarnw.com/page-2/
http://www.e90post.com/forums/attach...4&d=1278871872

[mathematics]

Rainbow DSP has a MOST input. Then you'd just add an amp or two and you'll have full control over your time alignment, eq, crossover points and slopes, and phase.

[ctuna]

So its a new unit that tranlates Most.
So it will decode the optical output of the BMW L7 Head Unit.
That would be good news for a lot of L7 owners.
Have you used it yet?
What's the price on the preamp and most adapter?
Look like its between 750 and 1k pretty pricy for a pre amp processor.

[mathematics]

Originally Posted by ctuna

Did you mean Helix DSP?
So it will decode the optical output of the BMW L7 Head Unit.

No, I meant the Rainbow DSP, which can take the MOST connection and also does wifi streaming


http://www.rainbow-audio.de/en/dsp/hardware/

[jin]

Originally Posted by ptpending

you can see three or four amplifier chip radiators on the sides of the amplifier, if you have skills to trace dead and replace it - you can fix it, otherwise it will cheaper to get another amplifier from ebay

Thanks i will open the amp up and see if i can see anything obvious like a burnt spot. I have no experience with doing this. Do you have any guides or pointers on doing this?