zappasBecause there’s a reason for that they don’t fair well or shut down. Be careful with your choice
Most that I see are not rated at 2 ohms.
Look for independent bench tests, like this Stereophile one.
Your PSB Stratus gold need an amp that breeze through very low "EPDR" (combined impedance/-phase angle) in the bass 50hz-100hz, also low impedance in the mid bass.
https://www.stereophile.com/images/archivesart/PSB97FIG1.jpg
Look for amps that can come "close" to doubling their 4ohm wattage into 2ohms (eg: 4ohm-200w/2ohm-400w) this means they have no problems with current into 2ohms.
Stereophile: Its impedance curve (fig.1) also suggested that it needs to be partnered by an amplifier capable of a healthy current delivery. Not only does the impedance drop to a low 2.72 ohms at 97Hz, but the -phase angle is quite severe through the midbass region.Cheers George