First sorry, My english Are really bad.
I have a 120 liters cabinet to my 15" JBL 2226h bass speaker, and going to make the cabinet a bassreflex cabinet, because the deep bass was really bad.
What port size may i use? 1 or 2 ports? Please help
spec for the speaker:

Hz: 30-2500
fs: 40 Hz
Re: 5.0 ohms (H)
Qts: 0.31
ms: 5.0
Qes: 0.33
Vas: 175 l
Sd: 0.088 m2
Vd: 689 cm3
Le: 1.75 mH (H)
Half space 2: 3.3%
Pe (Max)1
Overall Diameter: 388 mm (15¹⁷⁄₆₄ in)
Bolt Circle Diameter: 370 mm (14⁹⁄₁₆ in)
: 137 mm (5½ in)
Volume Displaced by Driver: 6 l