When companies load a cabinet with speakers...say for instance a 4X12" cabinet. It appears that most companies like Marshall, or Hughes & Kettner use 4 of the same kind of speaker. But on the other hand Bogner cabinets come with 2 speakers (Celestion V30's) and the other two speakers are (G12T75) different. And Avatar speaker cabs can come various ways as well. So what's the best way to go? 2 of the same? With 2 other different types of speakers? Or 4 of the same? Or ALL 4 different?