Low end loss when running two cabinets together

[Faldoe]

I have a Mesa 4x12 and just for another cabinet. The Mesa is 16 ohm, the other is 8 ohm so I have my impedance selector on my amp set to 4 ohm.

Each cab on their own has quite a bit of low end with my amps settings as they are. When I run the cabs together though the low end drops out a lot. Is this a common occurrence?

 

[Braciola]

Most likely, the cabs are out of phase with each other.
Through the unhooked end of the jack of a speaker cable hooked up to one cabinet at a time, make sure all speakes are moving forward when you click it with a 9 volt battery (positive to positive - negative to negative).

 

[scottosan]

Yes out of phase