best rca cable for deep controlled bass

What do you not like about what you hear now? It would help to know more about your system.

Once you get down around 80Hz and below, you can run romex and it won't matter. Cables that do present a bigger bass sound often do so at the expense of another range of frequencies. Or, much like ported speakers, they are made to store and release energy into a range. It is not rocket science and no mysterious thing. Cables are a system that are modeled with inductance, capacitance, and resistance. Why do you think some cables sound slow and some fast, some bloated and some not?

Not sure what the speed of electrons has to do with this discussion, but don't forget that the signal can be delayed going through different components like crossover parts. This can be milliseconds of delay and we can hear delays as little as 1/4 to 1/2 millisecond.