ALL woofers must have an enclosure in some form or another including an 'Infinte Baffle'.
An 'Infinite Baffle' denotes a woofer requiring a very large enclosure with a very compliant air mass. In the case of a 10-inch IB you would need two cu.ft. or larger to infinity for optimum performance versus the typical small and compact enclosure used for 'acoustic suspension' woofers. An IB woofer is self-sufficient and well internally damped while an AS woofer is highly dependent on the air spring and damping of a much smaller enclosure.
ALL woofers require controlled front to rear acoustic isolation, thus the need for an enclosure by some description.
Its very important that the woofer radiation flows away from the speaker without reduction or obstruction.