Cabinet Power Handling - How to determine?

[sws1]

How do you determine the overall power handling capability of a speaker cabinet?

I understand that a V30 (60 watts) and a H30 (30 watts) wired in the same cabinet is only 60 watts, since it is twice the power handling of the H30. (Twice because of teh 2 speakers).

WHat confuses me is that if I add another cabinet in parallel to the first at, say 100 watts power, I still don't know what the combined power rating is. If the 2nd cab only has 1 speaker at 75 watts, then the overall power handling seems to be 3 times the weakest link, i.e., 90 watts. But if the 2nd cab has 2 speakers at 75 watts each, the max power is 4 times the weakest link, i.e., 120 watts.

This seems to be the math used when wiring up a 4x12, in a series / parallel configuration. In essence, the series and parallel don't matter. What matters is the number of speakers. Although I don't know why.

What am I missing here?

[John Phillips]

If you are using only cabinets of the same impedance, power is divided equally between them too, as well as equally between the individual speakers in each cab.

In your first example, a 100W cab combined with your 60W cab is a 120W pair (twice the lowest-rated cab).

In the second example with the 75W cab, the total handling is still 120W, because the 60W cab is the limiting factor.

... and also in the last case with a 150W cab and a 60W cab. Unless your second cab has a rating lower than 60W (in which case the total is less than 120W, it doesn't actually matter what the rating of second cab is.

This does require that the cab impedances are all the same - if they're not, the power distribution becomes unequal, and series vs. parallel matters too. This really complicates things, and unless you're familiar with the 'rules', is best avoided.

[sws1]

So, if I have a 100 watt 4x12 cab (e.g., 4 greenbacks) running at 16 ohms, I can raise the overall power handling by putting another 16-ohm cab (or device ala Weber Mass) in parallel with the first cab. And if the 2nd cab has a higher rating than the first, I can get the total power output to 200 watts.

In summary, if I put a 100-watt, 16-ohm weber mass in parallel with a 100 watt 4x12 cab. I effectively can handle 200 watts.

(Now, I'm pretty sure that this can be done with the Weber mass.)