Explain this Audio stuff to me as if I'm 5....

I agree, this was way cheaper, will eventually upgrade head unit...

 

Just to add to this:
A dsp will give you whatever sound curve you want, but its all manual. There's not a "push a button and its done" kinda thing. It takes a bit or work to adjust a dsp.

But, if you are going for a good Sounds Quality system, a dsp is a must.

 

The RF DSP is $270 on Crutchfield - that's a good chunk of the way towards a head unit replacement. Not saying one way or the other is the "right" way to do things, but I looked at what it would cost to get aftermarket HU functionality out of my stock unit before buying. $200+ for DSP, $150-ish for front camera harness, etc. Helped me justify the $500 or so I spent on my Pioneer.

 

Buy a new head unit. Buy once, cry once.