Since inductance and capacitance for audio frequency filtering and other purposes tend to be very large why not "shift" the audio spectrum up to minimize there size?
For example, for a shunt-fed power amplifier(uses inductor instead of resistor to block ac so all the ac power gets shunted to the "ac load"(speaker)) the inductor must be chosen such that w*L >> R and 1/wC >8H and C >> 125mF. These are impossibly large and hence the shunt fed method is kinda useless for a full band af amplifier.
Increasing w to 100hz reduces the values of L and C by 100 which helps but cuts into the low frequency response.
But if we shifted the audio band up, say, to 1Mhz then it would reduce their values by a factor of 1M. (even shifting up 1khz is hugely significant)
So it looks good in theory but what is the real problem here? Is there any easy way to "shift" the audio signals with little distortion(ADC->DSP->DAC?) where one could benefit from such things? (maybe am or fm would work too?)