Hi Leemaze:
I'm not sure, but typically Wharferdale puts in really capable tweets and mediocre caps, which is why you can do so much with them.
Replacing the two smallest film caps you find in the crossover is where a lot of improvement can happen. Mundorf MKP's are usually good enough or Clarity CSAs
You may also wish to upgrade the biggest cap, usually in the bass section, and an electrolytic with film. Cheapies like Axon work a treat.