^^ If you want to supply the actual measured power output (not interested in brochure numbers) of the iNukes in various configurations, I'll give an exact answer.
In the mean time, here's how it works in theory, and in reality. The actual power numbers aren't important as they'll scale for other amps.
If you had a theoretically perfect SS amp that gave 100W/8R/ch, it would output 200W/4R/ch and 400W/2R/ch. This is called "doubling down", ie, that for every time you halve the load impedance the power doubles.
Place one of your Buttkickers (4R) on each channel and the amp can deliver 200W to each, or 400W total.
Place two of your Buttkickers in parallel on one channel (2R) and the amp can deliver 400W to the combined load, or 200W to each BK. It works out identically.
Now, in the real world, I've never seen am amp that actually doubles down. Some get fairly close, but most don't. My ROT for an AB/G/H amp is 60% and for a good PWM unit, maybe 80%. There will be outliers of course.
So the AB would give 100W/8R/ch, 160W/4R/ch and 260W/2R/ch. Note, very few amps are rated at 2R, so the 2R numbers could vary considerably, almost always down, especially for hifi amps.
Using the AB amp, if you placed one BK (4R) on each channel, each could deliver 160W to each of the BKs for 320W total.
If you placed the 2 BKs in parallel on one channel (2R) then the total load could receive 260W, or 130W per BK, less than using one a channel.
The reason for the above is most people don't run 2R loads and in the pro amp market, it's very competitive so manufacturers build to the minimum spec that think they can get away with and still get a sale. In the parallel examplethe load is going to try to draw double the current through a single channel vs a single BK/ch. As a result, all the internal series impedances, such as PCB traces, output devices, power supplies, connects etc lower the rail voltage and reduce the potential power. Offsetting this to some extent, is that only one channel is running and the other channel is not loading down the rail. Both channels will share some of the same series impedances, eg PCB traces and PSU, so it is nowhere near a 100% offset.
Last edited by A9X-308; 11-22-2016 at 05:45 PM.