I Have ALPINE MRV-F705 car amplifier and a 12'' BOSS subwoofer. I sucessfully connected to my pc after letting it be connected to a power suplly 3.5 amperes eleminator.

But the thing is the subwoofer out is at very low level. that is the sound is not much.. its only a little...

the amplifier dosnt consists any volume control

Please suggest some ideas to help me out.........