Soundlock makes a good point.
Jim Thiel, starting in 1988, while developing the CS5's discovered that, by using bass drivers that drop precipitously in resistance, that this had a side effect of pulling more current from the amplifier--acting 'almost' as an equalizer on the bottom/bass region.
I have not discussed this, but it seems plausible, AND if Jim said it to be true, I don't need much else to bolster this opinion.
So...with that said--an amp with lots of balls, doubling as the impedence drops more and more, as they do get into the 2 ohm region with the THIEL 3.7--should mate well with a 'Krell-like' bass performer. I don't ascribe to the Magtech amp, as I haven't heard it...yet, he's right on the mark in his assessment. THIEL's need current.
As a side note--one very hard earned lesson by Jim that year was, that virtually everyone exaggerated their current delivery on the amplifiers--very few did what the manufacturers claimed.
Good listening...
Larry