While you are just starting out the most important thing you can learn is that the audio community is overrun with idoliters.
Capacitor bypassing in crossover filter circuits is just another pagan god.
Bypassing has it's roots in power supply rails for equipment where low impedance is required through the radio frequency range or at some distance from the main capacitor bank where the inductance of the supply line necessitates additional local capacitance.
At radio frequencies a large capacitor becomes an inductor or at least the supply line will if the large capacitor isn't right near by a critical point for an active circuit.
A small capacitor in such an aplication will become the controlling element providing a low impedance point for your circuitry.
At audio frequencies for the purpose of a speaker crossover all capacitors are always in their range and behaving like capacitors.
Even the infamous non-polar electrolytic capacitor performs far beyond the capability of the best drivers.
The difference between film capacitors and non-polar electrolytics is measurably dramatic but when you build them into the speaker the performance is dominated by the characteristics of the drivers and the capacitors become insignifigant.
A bypass capacitor in the limited audio range simply contributes to the circuit in the same ratio in which it is implemented.
That is if your bypass capacitance is 1% of the total for the main and the bypass then the bypass capacitors characteristics are contirbuting 1% to the circuit and the main capacitor is contributing 99% of it's characteristics.
So if you use a non-polar electrolytic capacitor for your main capacitor and even though it's performance is beyond that of the best drivers in the world you decide to bypass it anyway with 1% of the total capactance coming from some type of film capacitor, then the difference will simply be a mere 1% of the way along the line between the performance of the non-polar electrolytic and the performance of the film (99% of the performance being determined by the non-polar electrolytic).
Should you increase your bypass to 10% of the total then you simply have 90% of the capacitor performance being determined by the main capacitor.
In a crossover filter a bypass capacitor always is a minority element while the main capacitor has near total control of the circuit.
Another misunderstanding in audio is that crossover componets do not influence the circuit most at high frequencies.
You've heard it said a million times that in the top octave is where you really hear the clarity or sweetness or what ever BS with a certain capacitor.
Truth is that crossover componets have their greatest influence near the corner frequency of the filter created with them (crossover frequency) where their impedance is comparable to that of the circuit.
As you get further from the a filter's corner frequency the impedance of crossover componets will go very high or very low and their influence over the circuit becomes less and less (the componets effectively are removing themselves from the circuit as you get further from the filters corner frequency).
One of the biggest lie's in audio is the film and foil capacitor.
Film and foil capacitors are claimed to be better because their ESR (equivilant series resistance) is lower.
However the impedance curve for capacitors looks like a 'V'.
It starts very high at low frequency and falls steadily until it reaches the capacitors self-resonance frequency (usually several hundered kilohertz depending upon the value of the capacitor) then the impedance climbs above the self-resonance frequency due to parasitic inductance (mostly due to lead length and the necessary length of those leads due to the size of the capacitor).
ESR is only an issue in the vicinity of the self resonance frequency, for the rest of the spectrum the capacitors impedance is dominated by it's capacitance and parasitic inductance.
Film capacitors typicly have very low ESR and as they approach their self-resonance frequency their impedance will usually deviate on the low side of what a perfect capacitor should be and then abruptly turn into an inductor.
The problem with film an foil types is that their ESR is even lower and their deviation from perfect as they approach their self-resonance frequency is even greater than that of a metalized film capacitor.
Not only that but film and foil capacitors are huge and because of their sheer size and the necessary lead length result in higher inductance and even more deviation from a perfect capacitor as compared to a metalized film type.
Bypassing capacitors in speaker crossovers is never of any use save one.
The capacitor bypassing issue is one of the fastest ways to find out that you are talking to or reading from a fraud to whom you never need pay attention to anything they say even though they could surely talk for hours about their cascading stupidity.