The Klimax *should* be able to drive the Kharma -- as to whether you like the result... you MUST try the speakers (any short-listed speaker) with your amps.
As to a suitable pre-amp: Linn makes its own which is expensive; admittedly, it's also very good.
I would really belabour the speaker issue: try as many as you can. For example, Kharma and Avalon often use similar drive unit complements, so Avalon could be another choice if you like Kharma.
The Wilsons' bass response: a frequency response plot I saw shows a small hump at around 50-70Hz if I remember correctly. If memory serves well and there is such a hump, it is not necessarily indicative of better bass -- rather, certain frequencies are pronounced giving the impression of more bass. Again, if I remember correctly, the Sophia have a smoother bass region than the 7. As always, however, it's a matter of taste.
A final note: the Proac 4 are arguably very good speakers. What do you want to improve on -- or, what don't you like about them??
As to a suitable pre-amp: Linn makes its own which is expensive; admittedly, it's also very good.
I would really belabour the speaker issue: try as many as you can. For example, Kharma and Avalon often use similar drive unit complements, so Avalon could be another choice if you like Kharma.
The Wilsons' bass response: a frequency response plot I saw shows a small hump at around 50-70Hz if I remember correctly. If memory serves well and there is such a hump, it is not necessarily indicative of better bass -- rather, certain frequencies are pronounced giving the impression of more bass. Again, if I remember correctly, the Sophia have a smoother bass region than the 7. As always, however, it's a matter of taste.
A final note: the Proac 4 are arguably very good speakers. What do you want to improve on -- or, what don't you like about them??