class d ohms vs sq

Do class d amps have different sound characteristics depending on if they're ran at 4, 2, 1 or .5 ohms?

I have a Hifonics BRX1100.D that I've had the opportunity to run every possible impedance and it seems like there's allot more changing than just the power output.

Now it could just be the combination of power output, type of subwoofer, type of enclosure etc that has me thinking this way but having heard all three of the different subwoofers before on different amps and then putting all those subwoofers on the same amp that there's definitely some differences.