After having the 2 together, you don’t really need another fan in the Grobo 2. The one included is almost to strong, I have it aiming semi up right now. I am going to check it a few days then I might even send back the 2nd fan I bought for it already. Not sure it would be needed as might be to much air then.
I have 2 Grobos going not even 10 feet from me and with the kitchen TV on, dont hear anything. With the TV off you hear a hum kind of. When I go in the room where the 2 Grobos are, right away, you hear the original Grobo way louder than 2.