Thanks Tobias. The mod is not so crazy, many people switch their R5 tweets for the RS 5 , keeping the same crossover. When I heard the RS5 at the store, the integration with the Rega mid was noticeable better. The owner claims that everything else aboutnthe R5 is identical to the RS5. To my ears, the RS5 powered with the naim or rega ss amps they were using was a very pleasant speaker, but I could not achieve the same effect in my living room, with my set and pp tube amps. Klipsch kg4, Heresy and the triangle Titus do sound fantastic here. So do a pair of Linaeum Ls 2 with my most powerful amp, a 40 wpc scott lk72. I believe that the issue could be a comination of directivity (horns & planar vs side radiating) and possibly impedance at the lowest frequencies. In other words, the regas are very good in their setup and terrible in mine. I wonder how much do I really need to change my setup to enoy them or if I should just sell them at loss and get something like an Zerius or a Klipsch RF7.