Just added a Polk PAD 2000.2 - Two channel amp(100 watts RMS per channel- certified) in my left bag. Used the passenger head set plug, converted to RCA's as input. Pretty good signal. Amp and Polk DXI 651 speakers add much quality to the sound and can be heard clearly at a couple blocks away. Neighbors love me... 92 Db at 1 watt. Good for a mid road speaker.
Very loud but clear if desired.

I have a pair of Premium Polk MM 651 speakers, but can't yet get myself to modify them to fit. They have a wider basket and require a spacer to fit the magnet, which is provided.They will also not allow the shelter- speaker cover to snap back on tight, so that will require some trimming. If I go there?

On a scale of 1 to 10, the DXI651speakers with the Polk amp combo, are a solid 8.5.
No comparison to OEM or the just a speaker upgrade without an amp.
I'm done with one for a while..
J