The rubicons show a bad recording i reckon so if the recording has been mixed on the bass heavy side it shows
Do you think, it might be that your speakers are allowing more music through your upstream equipment? I always feel that different speakers can be the most significant change in the characteristics of a system. Because of this, I am not surprised at your response to it.
I have done a lot of work on my electronics, mostly services and upgraded parts, only buying a new DAC.
This alone shows more of the recording quality and sometimes lack of quality of the cd albums I buy nowadays.
If I were in your position, I would not throw more money at the problem, at this stage.
Instead, I would tweak the system.
Bringing the bass through or tightening the bass, is more about taking out vibration and distortion.
Certainly worth experimenting with speaker feet/plinth and placement. Placement alone can reduce bass and bring it into alignment with the rest of the frequency response.
I placed Isopods underneath my Cd which took away distortion and cleaned up the signal significantly enough to hear the difference.
Cheapest upgrade I ever made at £18.