As a rule of thumb, we only recommend using higher end and more expensive capacitors for crossover positions that are in direct line with the tweeters / mid-range.
For tweeters:
As tweeters are always the most revealing part of any speaker system, they are the most common place where high-end capacitors are used.
Depending on preference in sonic profile, we recommend our Superior, Silver, Alumen or Amber Z-Caps, as the best choice for tweeter capacitors.
For mid-range (mostly upper mid-range):
Using higher grade capacitors like our Superior, Silver or Alumen Z-Caps can add better performance/sound, but it will to a higher degree depend on driver model, crossover design and filter order, compared to tweeter capacitors.
For woofers (separate bass section) / lower mid-range:
We recommend choosing good quality, but lower cost capacitors, e.g., our Cross Caps, Standard Z-Caps, Compact MKT caps or electrolytic “eleCaps”.
Specifically for electrolytic capacitors, we recommend avoiding capacitors with less than a 35VAC rating and no more than a 10% tolerance on capacity.
From a technical perspective it would generally be complete overkill to use expensive high-end capacitors for the low frequency area (bass), as the improvements in performance / sound of higher-grade capacitors, would not be audible at such lowe frequencies.
Voltage Rating:
How much voltage a capacitor is rated for in volts DC / volts AC is determined by the capacitor type and by the strength / thickness of the dielectric insulation film used.
For most passive crossover applications is does not matter if the capacitor is rated at 100, 200, 250, 400, 630, 800 or 1200 volts DC.
When exchanging capacitors on passive speaker crossovers it is therefore not needed to exchange with capacitors that have the same voltage rating as the ones you are replacing.
It is more important to choose the right capacitor type, depending on wanting to exchange the capacitor type one to one or if the goal is to upgrade the capacitors.
However, for certain higher-end capacitor types used for crossover positions that are used in direct line with the tweeters or the upper mid-range, it is an advantage to use a capacitor with a thinner dielectric insulation film as it will allow for a faster reacting capacitor with less unwanted “memory” effect.
This is why we use a thinner dielectric insulation film for our pure aluminum foil “Alumen Z-Caps” and pure copper foil “Amber Z-Caps” as these are meant specially for crossover positions in direct line with the tweeters and upper mid-range.
All the audio grade capacitors offered by Jantzen Audio will have sufficient voltage rating for application on passive loudspeaker crossovers (for home use).
When using capacitors in amplifiers it is far more important to be mindful of the voltage load of the amplifier and choosing a capacitor with a sufficiently high voltage rating.
This is usually most important in relation to valve/tube amplifiers.
Series filters:
For series filters, we generally advise using the same grade of capacitors for all positions, as all capacitors are in direct line with the tweeters.