I have a small radio receiver that has a 3.5mm mono line out jack. I have a BHI 10-2 MK4 amplified speaker for the car. When I plug the speaker into the radio receiver I don't get much volume. The speaker is rated for 5W rms audio output power. The radio receiver just does not have enough push from the line out jack. Does anyone know of a small amplifier that I could use between the radio receiver and speaker?