I mean pretty much what you mean. The parameters the amp is intended to operate at, as stated is 8, 4 and possibly 2ohm. Although 2 ohms is not recommended. I know it will operate in between these parameters but the intended wattage will be in between what is listed as well. By whatever means ss amps use to gauge the load imposed on it is what I mean by "internally selecting" the operating ohms. No manual switch like on my Ampeg for example. I don't know a lot about amps so, I'm probably not :?:using the correct technical terminology. The manual says it will operate best at 8 or 4ohms. I asked it to operate at whatever you get when you put 3, 8ohm speakers of different wattage together and expected maximum results. I thought that speakers and amps were designed in such a way to operate best at whatever specs the manufacturer intended, so you know what to expect power wise.
I bridged two 300w aguilars and one 500w Berg, all 8ohms. I'm not sure about the math and corresponding wattage but I maxed out the volume and didn't get as good a result as when I took one speaker out of the chain. The tone improoved as did the headroom. I miscalculated what the output should be and expected it to power all speakers with room to spare. Honestly, I don't know if I "strung" the speakers together the right way. Before now, I used ss heads or combos set at 8 or 4 ohms and matched it with a speaker of the same ohms and didn't worry about it after that. Ahhh, the simple days. Anyway, I hope stuff that I say on the forum doesn't put anyone off from buying gear they may be interested in. I'm just starting to learn about gear and still have a ways to go.