preamp

I installed a Joying head unit recently on my Nissan Altima with Bose option. It works great, but I chose to wire the pre-amp outs (RCA connectors) to the OEM Bose amp that sits in the trunk. There is too much hiss and not enough amplitude, as I presume that the preamp outs don't supply enough...

Looking to buy a quality USED dash mounted EQ. 3 or 4 bands is fine. Would like to have subwoofer gain control, subwoofer x-over, front/rear fader, and at least 4 Volt output. Need front, rear, and subwoofer output. Would prefer a nicer unit like AUDIOCONTROL ECLIPSE ALPINE KENWOOD...

I recently bought a kenwood eXelon x794 HU for my suv looking for better SQ. I notice that the HU has a Lot of settings for the EQ and sound processor area; DO you recommend or even if is necessary to put an additional equalizer/crossover? Suggestions... I got a 4 channel amp for my components...