Thanks!
It’s a 9mm quality and very quiet computer fan mounted to the outside of the speaker in the discant hole. I usually keep the power supply for it on 6V or 9V as 12V is not really needed except perhaps if the box was really packed with flowering buds, or it was way too warm outside in the room. On 12V the fan is also noticeably louder than on 9V (and a bit more smell gets through…). Even at 6V it keeps the temperature in the box at only 7-8 degrees Celsius more than outside room floor temperature.
DIY carbon scrubber; a miniature version of the commercial ones. The “wall” of carbon in this really tiny one is a bit on the thin side (15mm), and smelly strains like MK do leak out a bit, but not much as the air passes so much slower than with commercial extraction fans…
Have also tested them scaled up, both the scrubber as well as using double and even triple 120mm fans boosting each other in a channel made of cardboard. I would say you could aerate even quite big LED grows very quietly with good computer fans, like Noctua, if you just place many after each other, not side by side. I used a small Noctua fan in this upgraded version of the speaker, where a small COB light is in the middle and the scrubbing is also of a very different design…
("Jungle-woofer" = super-stealthy hifi-speaker growbox)
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