I am a 3rd year engineering student currently working on a project where I need to basically make an ultrasensitive metal detector.

Basically, I need to create an alternating magnetic field by connecting an audio amplifier (which is also connected to a function generator generating 1kHz sine wave) to a solenoid. long story short, I need to put a bandpass filter in between the audio amplifier and a solenoid. I need some tips on how to do this. I tried to use filter design calculators available online, but to me, the major problem seems to be that I need a filter that can handle high current input as well as high current output (~1.5 A, I_rms) with minimal voltage drop. The resistors on the bandpass filters I made would just burn due to high power input. I guess this leads to a more general question: How do you create a bandpass filter that can handle high power input with minimal power loss?

So far, I've focused on passive filter using RLC, but answers involving active filters are also good to me, though I don't really have any experience with it.

Additional information:

Setup: I have two solenoids: 1.transmit coil which will generate alternating magnetic field 2. gradiometric pick up coil (or receive coil) which will sit inside the transmit coil. The pick up coil generates minimum voltage thanks to the gradiometric design. However, once metal is inserted inside the pick up coil, either the eddy current or the magnetization will induce voltage on the pick up coil, which will be measured by DAQ. The problem is that total harmonic distortion (THD) is much more amplified on the pick up coil (Ideally, there should be none). I believe this is due to the fact that the voltage induced in the pickup coil is proportional to the derivative of the current. THD doesn't really show in the transmit coil (below noise level).

I am a 3rd year engineering student currently working on a project where I need to basically make an ultrasensitive metal detector.

Basically, I need to create an alternating magnetic field by connecting an audio amplifier (which is also connected to a function generator generating 1 kHz sine wave) to a solenoid. long story short, I need to put a bandpass filter in between the audio amplifier and a solenoid. I need some tips on how to do this. I tried to use filter design calculators available online, but to me, the major problem seems to be that I need a filter that can handle high current input as well as high current output (~1.5 A, I_rms) with minimal voltage drop. The resistors on the bandpass filters I made would just burn due to high power input. I guess this leads to a more general question: 

How do you create a bandpass filter that can handle high power input with minimal power loss?

So far, I've focused on passive filter using RLC, but answers involving active filters are also good to me, though I don't really have any experience with it.

Additional information:

Setup: I have two solenoids:

1. Transmit coil which will generate alternating magnetic field.
2. Gradiometric pick up coil (or receive coil) which will sit inside the transmit coil.

The pick up coil generates minimum voltage thanks to the gradiometric design. However, once metal is inserted inside the pick up coil, either the eddy current or the magnetization will induce voltage on the pick up coil, which will be measured by DAQ. 

The problem is that total harmonic distortion (THD) is much more amplified on the pick up coil (Ideally, there should be none). I believe this is due to the fact that the voltage induced in the pickup coil is proportional to the derivative of the current. THD doesn't really show in the transmit coil (below noise level).