I used the Crown XLS 2502 to power a pair of Aerial Acoustics SW12 subs that I’ve converted for passive use, and the amp worked well. It has a high/low gain setting which helps get you in the right range then volume adjustment for each channel. It also has a useful crossover function designed toward subwoofer use. I happened to use the setup with a miniDSP 2x4 HD so I could add some EQ, but that isn’t necessary. The Crown has led indicators on the front and I never saw it get anywhere near clipping driving the pair of big subs.
Also, the amp sounds too darn good driving the mains in a 2-channel system for its low price.