I found that the bass extension is lower and midbass is warmer with the Infinity Primus P162 than the Polk RTi4. While the bass extension of the RTi4 is not as low as the P162 the lowest bass the RTi4 is capable of is just a little bit more dynamic. The midrange of the P162 is full and pure, but the imaging is somewhat less 3D-like than the RTi4. The P162 is refined and diaphanous in the high frequencies if somewhat less dynamic than the RTi4. I found that while the Polk RTi4 performed a little better than the P162 in some areas I like the P162 better overall. I think I would probably like the Polk RTi6 a little better than the P162 though.

If you are looking to replace the Polk RTi4 with the Infinity Primus P162 it is probably not worth it, the Polks are about as nice with less bass.