Up grading equipment

Planning to upgrade everything can I connect a 6in intake fan to a 4 inch carbon filter that might sound stupid to some people but I was just wondering if I can do that

It’ll make your fan work harder than it should and you would run the risk of burning it out. get either a 6” filter OR even an 8”-10” filter which would make the air flow even easier for the fan.

technically you can its not advised but if your going to lower the fan to under the cfm for the filter u should be fine. what your looking for is a 6 to 4 inch reducer duct

I run a 6” ac infinity fan and a 6” filter. Gonna upgrade to 8” when I need a new filter