In article ,
(Jeridiah) wrote:

For reference - fan is 8" with a baffle rated at 180CFM and 6.5
sonnes.

Egad. First thing would have been to pay attention to the sones rating
before purchase, or return it and buy one with a _much_ lower rating.

If you want to choke it down, it need not be all that complicated - put
a damper in the duct.

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