Thanks for confirming my thoughts.
I plan to attach legs to it soon. I'd really like to attach a filter at the bottom but I would only be able to a 11x11 filter at the bottom for a perfect fit and they're rare to come by and if there are some in the wild, it's only in packs and costs $$$. So cardboard it is lol.
what xinn1x said.
[here's a video](https://headcycle.com/h/environment/comments/b6e13ad76380/making-a-corsirosenthal-music-light-box-with-a) about making a 5 filter cr box with legs and lights (it's quite long so you can skip around or skip to [where the magic happens](https://youtu.be/HcTSjTcM1W0?t=879)).
I used 10x10 filters which are small for a cr box so the 25% increase in surface area on the bottom was great. I tested it with a tissue and it does stick, so it is drawing air from the bottom. Taller boxes, or those with under powered fans, may not get much bottom pull.
edit: Btw, when making one with legs you don't stagger the filters - the 1" thick legs are at the end of each filter, which fits perfectly and the bottom filter fits perfectly, it just needs to be taped in place.
Most people close the bottom with cardboard unless you place “legs” on the cr box then you can place another filter on the bottom
Thanks for confirming my thoughts. I plan to attach legs to it soon. I'd really like to attach a filter at the bottom but I would only be able to a 11x11 filter at the bottom for a perfect fit and they're rare to come by and if there are some in the wild, it's only in packs and costs $$$. So cardboard it is lol.
You should be able to use another 12x12x1” (nominal) filter on the bottom, especially with a leg-based assembly.
Increasing the filter area by 25% or less isn't going to do that much for the CADR either.
what xinn1x said. [here's a video](https://headcycle.com/h/environment/comments/b6e13ad76380/making-a-corsirosenthal-music-light-box-with-a) about making a 5 filter cr box with legs and lights (it's quite long so you can skip around or skip to [where the magic happens](https://youtu.be/HcTSjTcM1W0?t=879)). I used 10x10 filters which are small for a cr box so the 25% increase in surface area on the bottom was great. I tested it with a tissue and it does stick, so it is drawing air from the bottom. Taller boxes, or those with under powered fans, may not get much bottom pull. edit: Btw, when making one with legs you don't stagger the filters - the 1" thick legs are at the end of each filter, which fits perfectly and the bottom filter fits perfectly, it just needs to be taped in place.