Small Sub enclosure

[NickD85]

So I'm just about done with my custom fiberglass subwoofer enclosure. Today I filled it with water; it holds 11 liters, or about 0.39 cubic feet. The sub I have my eye on has a recommended sealed enclosure size of 0.40-1.8 cubic feet. I'm clearly at the very low end of the spectrum, and was wondering if this will have a noticeable impact on the performance and sound quality of the sub. I remember one of you guys saying there are tricks that can help with a small box- like stuffing it with cotton. Any thoughts or suggestions?Thanks,-Nick