Airflow / Cooling:
A much better solution are improved fan-plates. I've made new ones, which are much more efficient and the fans are more silent. A friend of me has got a CAD drawing from me, and I expect tomorrow the first new fan-plates, made on a CNC machine. With this plates, you still have a stable box, are protected from touch the running fans and you have optimal air-flow inside and outside of this box/tube. It will help to keep the whole unit more quite and cool, which will be especially necessary by the next tuning steps.

Because of the noise users start to change fans. The default ones are really noisy, but also powerful ones. I can only warn everyone to replace the fans by other ones, if you don't really know what you are doing! The default fans have a high static pressure and airflow rate. I will look for acceptable, fan replacements which are not so noisy in the next days and will let you know.