Hi I have recently upgraded all the speakers in my 2006 s60r added 2 4 channel amps in the boot along with a sub I want to keep the hu 850 headunit and have connected a din plug adapter wire to the headunit but my problem is there does not seam to be enough power coming out of the headunit as the amps are cranked nearly all the way up but still not driving properly the next thing to try I've been told is line level converters coming out of the amp under the drivers seat I was just wondering if anyone has tried this or has any other suggestions.