Head unit cross over or cross over that comes with component speakers?

[Orestp]

Hi - I'm considering using the 3-way crossover that is in my head unit (Pioneer DEH-80PRS) and outputing the head unit to a 6 channel amp to run a 3-way speaker system with left & right highs, mids & lows.

I plan on buying a component speaker set and not using the crossover that comes with the speakers, but uning the crossover in the DEH-80PRS instead.

Some sales people have told me that they would only use the crossover that comes withe the speakers, and would not use the crossover that's in the head unit (although they did not explain why).

Doea anyone have any advice?

Are there reasons why using the crossover in the DEH-80PRS would not give results as good as using the crossover that comes with the speakers?

Thanks,

OP