the box 18LB100-4N Ersatzspeaker 18"

For this cost & @ the required 4 ohms for my power amp, this "big'un" certainly fills its role of punching out the lower end of my acoustic guitar.
I have carefully made a ported/reflex enclosure for this, using the speakers specifications and using a good "active crossover" Rolls minimix does a perfect job for me.
The resulting sounds is very impressive, never fails to bring good comments and interest from audiences.
Arrived @ my house 3 days after ordering it. "it's big" and it's powerful.