Audio upgrade

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.

Sorry, forgive me if I'm completely getting this wrong, but aren't most cars typically a 4 ohm affair, and Volvo speakers are 8 ohms? Would that not have an impact or am I talking complete Boloc*s?

Are S60R/V70R Dyn Audio speakers 8ohms or 4ohms? Would that make a difference?

Also.....

:worthless

As Lee said, we need pics :D

A line level converter from the amp would probably do it, though I would have thought the signal to the boot from the HU din wouldn't degrade that much. Is the cable of good quality?

Sorry for hijacking this thread any suggestion on which is a good headunit want to replace the double din headunit on my 1998 v70 r