VCF with inductors

[Rowena Larkins]

I noted Jon's question and started thinking

A crossover in a speaker box uses inductors to define the cutoff frequency.
Is it feasable to use a transformer type arangement, that is an inductor with 
some extra turns around it, to form a variable inductance ? The extra turns 
would have a DC voltage applied accross them to give a electro-magnetic effect, 
and this DC voltage would be the control voltage?


Rowena