See link to test https://audiosciencereview.com/forum/index.php?threads/i-measured-10-subwoofers.49042/post-1756731 It looks like @ 20 Hz they output 94 dB with 74% THD and 90 ms group delay. I would not call that good. They will output 107 dB @ 40 Hz to 60 Hz with 15% to 20 % distortion which should be OK for what you are looking for.sb 2000 pro x 2 will be good at 20hz or not?