I did some digging around. JBL use this Vandersteen idea in their K2 speaker. As you are probably aware capacitors vary in quality and linearity. If you bias a polypropylene cap then the distortion products (due to non-linearity) will still be there but they will all be even harmonics (more benign to our ears). Also the circuit should be such that it won't matter about the battery aging (normally connected to a 1 K or more resistor). It does mean that the circuit requires two much larger (more expensive) capacitors in series of twice the value of what you would need if you used one capacitor. Since capacitor non-linearities tend to increase with size, a lot will depend on a the careful choice of components if it is to be an improvement over a single capacitor.
It also opens the door to using polarized capacitors in a crossover although I don't think Vandersteen does this (he uses polypropylene)
Anyway - interesting stuff - I hope this helps. I have found an AES paper on this subject if you are interested.
It also opens the door to using polarized capacitors in a crossover although I don't think Vandersteen does this (he uses polypropylene)
Anyway - interesting stuff - I hope this helps. I have found an AES paper on this subject if you are interested.