Still confused with those watts!

[Nephilymbass]

Firstly, who are you playing with, Meshugga? 300 watts into a 410 is LOUD. Even the 175 Watts that the 300 watt amp into 8 ohms will be bloody loud. The difference in volume between the two (175 and 300) is nominal. The same difference in volume when adding the second cab will be the second cab, not the added wattage - of course both together will be a noticeable difference - but that's because it's TWICE the thhe difference either on their own.
But honestly, unless you're playing metal in a band that doesn't use FOH, 300 (or even 150-175) into a 410 will be more than enough for MOST bands us mortals - in particular newbies - will ever play with.

That's a bad reference lol meshuggah doesn't use amps lol. They all run axe fx direct and before that they used line 6 vetts 2s run direct.

 

[Eminor3rd]

Yes

 

[Gaolee]

Any amplifier can run a single 8 ohm cab, it's just that most amp companies don't show wattage figures for both, which is dumb. Personally, 300 watts into 8 ohms will not quite make it in a full band setting at a club, especially if you are concerned with headroom...but adding a second 8 ohm box will be perfect.

My biggest, most ferocious amp "only" has 400 watts. I have never, ever had to turn it up very far. In the end, watts are just numbers.