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We know that capacitors with same capacitance in parallel reduce overall ESR ,and dig quite a bit "deeper" at same resonance point "valley" as well.
Some researches suggest that anti-paralleling such identical capacitors (non-polar) make such effect more pronounced:
Since capacitors in speaker crossovers are mostly non-polar, which would certianly be safe for anti-parallel, but with "resonance point" altered, would it screw up "transition" between driver's frequency? Has anyone tried?
Note that your figure 6 shows the frequencies of MHz, not Hz.
This kind of neutralization of the capacitors series resonance will only affect the extreme upper range, well outside the audio band.
So while it might be of some benefit for AC power line filters in terms of RF suppression, it would have virtually no effect on an audio band speaker crossover behavior.
Note that the authors conveniently seem to overlook the result of placing a smaller value capacitor in parallel with the larger caps, one with smaller physical dimensions, and a much higher resonant frequency.
That is why power supply bypassing, and filtering situations often use more than one capacitor at a critical location, with staggered resonant frequencies via a range of cap values that cover a much wider range of low ESR resonant frequencies. A good rule of thumb for these situations is to use a cap value that is two decades smaller in value, with as many as three different sized caps in parallel, to provide a broad band region of lowered ESR at the RFI frequencies.
When there are large electrolytic's in use in a crossover, it is common practice to use a smaller value film cap as a bypass for the higher frequencies, mainly because the electrolytics have such a large amount of internal inductance.
Even the larger film caps, due to their physical size, can benefit from a smaller bypass film cap.
These smaller caps can then be of a higher grade than the larger film caps. Perhaps a set of polyester (mylar) larger caps, bypassed with a polypropylene or styrene cap.
Thank you for carefully detailed answers! :)
I figure that caps for speaker crossovers mostly works within audio frequency so I thought phenomenon would be similar but just occur in different frequenct range.
And as for bypassing, I'm yet to find any article tried "big one with an anti-paralleled tiny pair."
Since there yet to be a negative report, I may do this experiment myself. A sweeping frequency audio file should easily reveal if "transition" would remain smooth with such configuration.
Unless you are playing 60hz "music" you need to go beyond power line theory.
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