Yes, one cap is better than 2 in series, but I doubt you'll be able to hear a difference in most cases. It depends on the quality of the capacitors. What you can do to improve 2 series caps is adding a 220 ohm resistor to ground from the center connection between the two caps. This bleeds the offset DC leakage down to ground.
I put them closer, realy had a good result, sounds more like one source, thanksHenk,
You couldn’t get the tweeter closer to the mid?
dave