Wow, thank you for all this work and info. I'll start digging into this! I feel like I skipped an era and now I'm cool again xD DIY is definitely sth I'd do.

Turning the volume up too high is probably not the way my ears will go. I like to go down till it's too quiet and then just one up. I like it in the background and I know the numbers by heart for "alone at home" and "walking by the busy road" ;)