10” 4th order Enclosure help

[209er]

Looked at space I’m assuming a 6th order for a 15 neo 3.5. Should be much better for my space? 

[Joe X]

Looked into this last one and it works very fine on 4th order bandpass, excellent low end extension down to about 20Hz and overall low group delay so near sealed clarity. Space wise that enclosure would take about 7.5 cubic feet net (plus port and wood displacements) so compatible with your space, maybe a little taller like 17.5H to better fit the sub.