And those Kenwood speakers are around 8-10 years old I'm guessing. they were some pretty decent $60 coax speakers back when I was in high school... I had a pair of those and some Pioneer TSA-1660 6.5" coaxes that looked exactly like those.. they said 60w RMS on them, but I fed them upwards of 200W per channel for a long time and they took it. eventually I got myself some Focals and stuck the pioneer's in my sister's Honda, but they are still sounding good to this day...
trust me, those speakers are better than most of the crap you can buy today.. audiobahn, bah... the Polks you now have are going to be noticeably better, but keep the Kenwoods for backup just in case you blow one of your new speakers.