MEASUREMENT

ELECTROLYTIC CAPACITOR
LARGE FILM CAPCITOR
SMALL FILM CAPACITOR
OIL CAPACITOR
AFT URUSHI CAPACITOR
SUPER / HYBRID CAPACITOR 
PARALLELED CAPACITORS

We all know that different capacitors sound different. 

Some boutique audio components use silver, gold, bling-bling materials and costs an arm and a leg.  

Here is what we do about them. Instead of guessing or reading someone's reviews,  we use LCR meter and measure phase, impedance and other parameters from 1Hz to 5MHz.   After capacitors pass our measurements test, we put them in our audio system and make final judgement by listening. 

Ideal capacitor will have -90 degree phase at all frequency range. However most capacitors cannot even cover audio frequency without crossing 0 degree. At 0 degree the capacitor is no longer a capacitor. It is soon to be an inductor!

Here is an example of not using ceramic disc capacitor.

Vishay 2LS Ceramic Disc 22pF 100V:
maintain almost -90 degree all the way up to 5MHz (this is great), but
phase response is irregular everywhere, ugly!! I would not use this cap for audio analogue signal path.