Audio Systems: subs wont work, bose amp, vw jetta

Question
i have a 1997 vw jetta glx vr6 with bose stereo system I've had an aftermarket head unit in for awhile i went to hook my subs up and the amp has good power and ground and rem wire is good but they dont hit very little sound comes out all ather speakers work fine L&R audio plugs are hooked up rem ground power every thing is good i dont know what the problem is ive never hooked anything up with bose stereo wat do i need to do to get the subs workin

Answer
Bose uses non standard voltage I/O interface levels.  Most aftermarket amps will drive to full power with 1v audio and your aftermarket head unit is probably giving the 1v out.  But, Bose amps require a 2 or 3 v audio drive. So, that is the problem is you are using a Bose amp to drive the sub.

You may need to use a Hi-Lo adapter to get enough drive voltage to the subs.  Go to installer.com for all kinds of hi-lo and other adapter kits.

If you need more, give me the model numbers for the head unit and the sub amp; that way I can learn the technology you are dealing with.