Wanting to build a 3-way fully horn-loaded speaker system

[grec13]

"What would you recommend to rich 300hz in PPSL -10" or 12"? "

The Dayton 295-120 will do 300hz at 100dB/2.83V/1M and be -3dB at 27hz in a 24" cube PPSL.

I am also designing a 25hz PPSL with eight 8's that will cross at 400hz and be 100dB.

Here is a quad 295-120 PPSL.

pudhpullsubquad12_zpsb771020a.jpg Photo by fullrangebates | Photobucket

(cat is optional)

Thank you DJK.
I'll try 12".