Has anyone played through a 4x10+15 in one cab? Like the Ampeg SVT-1540HE or Mesa Powerhouse 1000? How do they compare to the sound of two separate cabs? The 10's in the Mesa are surrounding the 15, whereas the 15 is under the 10's in the Ampeg. I'd think the Ampeg would sound similar to a normal 4x10/15 stack. Correct? Thanks.