I guess an HU can have a difference with settings. 
Just get a Pioneer amp. For speakers, you can't fail with the Pioneer A-series (not components, just speakers). Same goes for the D-series. D-series will hit harder, but the A-series sound better overall.
Just get a Pioneer amp. For speakers, you can't fail with the Pioneer A-series (not components, just speakers). Same goes for the D-series. D-series will hit harder, but the A-series sound better overall.