I convinced my son's friend into ordering a SA 12 However he wants to put it into his existing sealed box that is ~1.65 ft^3. I know the recommended sealed size is 1 ft^3. What effect will this have? Any less power handling, less sound quality (yes he was looking for sound quality:-), etc. Thanks for your help.

Is the box a net volume with speaker displacement accounted for?

no before displacement.

Less mechanical power handling -- but it will sound just fine.

If worried then tell him to add some wood blocks in there and and bring the internal volume down to 1 ft, another alternative but smaller power handling will be the only factor with a bigger box.

It will reside on the larger side of recommendations even after speaker displacement but will only suffer a little less power handling. Will still sound excellent with some very good low end.

Thanks guys for the super quick replies Instead of wood blocks can he use polyfiber fill? If so how much, 0.5 ft^3?

Thanks guys for the super quick replies Instead of wood blocks can he use polyfiber fill? If so how much, 0.5 ft^3?

No, It will do the exact opposite and make the speaker think it's in a larger enclosure.

Wood blocks would be a great idea to take up some space.

Looks like we'll be cutting some wood blocks. Thanks everyone