BD pipes filter circuit questions

[porkchop61]

Hi all-
Just finishing this project, and I had a question on the filter circuit used for this project.
The picture of the circuit is here:
http://diyaudioprojects.com/Speakers...pes/filter.png

I'm going to start off without the filter to see how I like the sound. My questions are how does this circuit affect the impedance, and which speaker gets the capacitor in parallel?

I know the impedance will change with frequency, but I'm using 8 ohm drivers, and I want something close to 4 ohms for matching to my tube amp (SE KT88).

I'm assuming the front speaker gets the capacitor in parallel, as this filter is to tone-down the brightness per the article. Is this right, or does it matter?

Thanks in advance.

Regards,
Glenn