Not sure how much bass you are thinking of when you say "strong bass". The Stealthbox will put out some satisfying low end on the factory DSP amp sub channel. It is not loud bass but it is definitely lower, tighter and more substantial than the wimpy OEM subs. I have not heard the Stealthbox connected to a non-DSP OEM stereo, only a DSP stereo.
As far as ruining the amp is concerned: If you continually crank an amp with a speaker than is half the required impedance, you will create more heat and distortion at the amp and it will likely fail earlier. How much earlier... who knows.
The Stealthbox is a great addition for your X.
