Last time we used MeanWell SMPS we ended up enducing lots of RF noise due to EMI radiation. They tested to comply at 80% load, any variation causes them to go outside of specs badly. 

Work around was to build all PCB's using 4 layer topology, where top and bottom layer where solid copper for shielding, internal 2 layers are tracks. We also used top layer as heatsink for power components as it was 3mm aluminium plate. Had EMS company to prototype PCB's: http://www.papcb.com/flex-pcb/ they do lots of high tech PCB assemblies. 

Alternative is to place SMPS's in separate fully enclosed metal casing and also place filters on in/out wiring to cut the noise.

Hi,

Definitely possible, you need to find a dsp board with 12 output channels (like Shark Analog devices or MiniDSP). Sure audio are making 6x100W amplifier boards for nothing in Class D architecture. You just need to combine 2 amp boards and the dsp and you'll have 12 channels dsp amplifier. By the way, Focal and Pioneer are making really good digital amplifiers for car with multiple output and also a good guid for tuning the car. But if you choose an Analog devices dsp you can program at least 1000 biquad for your tuning, so you can make your crossover / peak eq / all pass for time alignment / virtual center / delay / limiters... If you need some advises for car tuning don't hesitate to contact me, i'm acoustical/application engineer, i do a lot of tuning on premium car with this kind of amplifiers. Jut a small question, you're not using a subwoofer and center for your application ? in this case you can drive 2channels in doors (woofer + passive mid/tweeter) + 1 channel as center + up to 3 coils subwoofer with the last 3 channels

Hi,

I was making research for while for this amplifiers. However I would like to drive 12 speakers instead of 8, is it possible. I would like to build one as digital car amplifier. so each door has 3 speakers in total 12 speakers. Is it possible set freuquencies for each speaker in this setup?

Thanks