If the suckout is narrow enough (in frequency), it will be almost unnoticeable. That’s good news, because (1) 60 Hz is too low for most porous absorbers to be terribly effective, and (2) if it’s a true node, adding more volume via DSP will not be very helpful. So to my way of thinking, if you’ve found the listening and speaker positions that satisfy your ears otherwise, you could consider just living with it.
The other solution would be subs placed differently from your main speakers. That can be effective, but integrating subs optimally is not a simple task, by any measure.
The other solution would be subs placed differently from your main speakers. That can be effective, but integrating subs optimally is not a simple task, by any measure.