Subs are a pain in the pitootie. Adjusting it so it sensed not heard means that you have to unplug it (no power switch) to do a comparison...so I bought a second one??? The first configuration left and right of center just wasn't right Lots of muddy overbearing bass. They are currently stacked and turned way down. I'm pairing them with high efficiency speakers and the gain curve of the speakers doesn't exactly match the subs so they're set to work best at a specific volume.
The biggest issue is the recordings. The amount of bass energy from one recording to the next is exaggerated with the subs. Depending on the track used to set them, the next tracks have way to much or way to little.
That being said "Poema" by Eduardo Niebla • Antonio Forcione is way to much fun to be without them.