Looks like there’s still no takers willing to put it on the line, and
post up the 8ohm, 4ohm, 2ohm wattage measurements just before clipping,
to see if they are "almost" doubling the wattage for each halving of
load, so to prove if their amp/s are going to drive these types of
speakers close to their best, not just "satisfactorily"!
George, you like to promote GaNFETs as a thing in class D amps. But from this post is seems that you are unaware of something that GaNFETs bring to the table: very low 'on' resistance, often less than 100 milliohms. The devices we are using have an 'on' resistance of 60 milliohms.
That's lower than most linear output transistors! So a class D amp has no worries behaving as a voltage source provided the power supply can provide the current required into lower impedances. IOW less technical terms this simply means that doubling power into 2 ohms is no worries as far as GanFETs are concerned (and for a lot of other switching transistors as well). Our prototypes can double power into 2 ohms and we're not even trying to make it do that. It comes with the territory.
Whether its worth it or not is an entirely different subject as all amplifiers regardless of technology have higher distortion into 2 ohms which is audible as increased brightness and harshness. You can see this in the specs (if 2 ohms distortion is even specified, but you can also see it in the 4 ohm spec as opposed to 8). Further complicating matters is the critical nature of the speaker cable, which must be kept very short and also must have a fairly heavy gauge. At that impedance its very easy for the cable to contribute to the overall source impedance seen by the loudspeaker!
In a nutshell, 2 ohm loudspeakers are impractical and the ability to drive a load like that is over-rated. Sure, we like to play with muscle power and boast about it, but in the end it doesn't matter if you can weld with your amplifier; its intention is to sound like real music (not a hifi, unless its intention is simply to make money) and no amp is going to do that driving such a low impedance.
Another way of putting this is if you want to get the most out of your amplifier dollar investment, that dollar is best served by a loudspeaker that is a higher impedance, assuming that high quality sound is your goal. Any loudspeaker manufacturer can cause their speaker to sound smoother and more detailed by raising the impedance because when the amp makes less distortion, it sounds smoother and more detailed... Funny thing is, everyone knows this, its not some sort of hidden inner sanctum secret. But we still see these silly low impedance arguments when the simple fact is that the low impedance doesn't benefit anyone. You'd think that in high end audio where sounding real as opposed to sounding like a hifi is well understood, but here we are in the 21st century and this nonsense is still going on...
