Well it's been a while...

Still enjoying my active setup, when it is plugged in.

Had electrical work done so felt like I have moved house several times and not gone anywhere. What I have learned is that an active 4 way speaker is more complex to plug back in than a passive setup...

My conclusion is that active is still better than passive. Even just at a basic level, if you crank it right up, the amps hardly get warm.

The AK4458 has more noise on the output, but I am still using the ADAU1966 filter board. 

I have mostly forgotten what I was going to do next, it's all in a box somewhere around here... Oh that's right, the XMOS board wouldn't see the flash chip.

You can change the port used for the data lines, and on any port the data pins 1 and 2 didn't seem to work (0 and 3 did). Not really sure on that, unless I damaged the chip when soldering. Unlikely to kill 5 sets of output pins though! Looking online other people have had issues getting flash chips to work. I did have some alternatives to try. Which must also be in a box somewhere........