What are you trying to achieve? You have a pretty good film cap already. The only identified issue with film caps is a potential for mechanical resonance specific to a frequency but audiophiles make up all kinds of things like posts in this thread. Caps can be in high or low pass filter networks. They are critical in both. That's simple circuits. Whether the signal passes through them or is shunted to ground through them the effect is the same. You don't have a cheap electrolytic so temper your expectations. There is a reason some quite expensive speakers use sort of average capacities.
