Mini/main DVR tuner usage?

OK, someone please help me to understand how the mini works as far as tuner usage from the main DVR unit. As I've read and understand, the mini takes over one of the tuners from my Roamio, which has six tuners. The leaves five for the main DVR unit's use. So, as I understand it, I could have up to five minis, each with it's own tuner, and still have one tuner left for the main DVR. But I've read that we can have up to eleven minis on a Roamio DVR. How is this possible if it only has six tuners?



What am I missing? I'm certain there is something that I've just misunderstood but I'm really having a hard time making sense of this.



Thanks to anyone that can help me to clear it up.



- Byron