This is information to all OB speakers fans. If you dont believe in acoustic silence and only trust what you are hearing , stop reading my post and keep enjoy in bass performance open baffle design . But if you have open mind -Baffle size must be bigger than length assume low frequency wave , For usually size baffle 20-30 " OB speakers bass performance starting from approx. 100-120 Hz https://www.acousticfields.com/wavelengths-in-our-rooms/