Audiocontrol 2 channel input?

Depending on the adjustability of the crossover points / slopes in the head unit, an external x-over may provide better flexibility.04 MDX - Clarion DRZ9255 / MB Quart QAA4250 / MB Quart QSD216 / Orion Concept 97.2 / JL Audio 10w6v2

91 GMC Syclone - Delco tape deck

90 Syclone powered 2wd S10 (for sale) - Pyle CD / Fosgate 4x6

In the past I've always achieved better sounding results with and external x-over. Flexibility for sure...but I just always end up with better SQ and a decent db boost with a "feeling" of more control. I know the 500/1 is a quality piece but I've always felt the main focus of engineering on a mono or sub amp is performance etc... an external piece designed specificly to do its job always seems to work for me. Pretty soon they'll probably combine everything into a head unit/pre-amp/parametric EQ/24db slope 3-way x-over/1000W mono amp/400W 4 channel amp that you can fit in your pocket.