I was listening to some random metal station and heard HipHop esque bass beats in the background to emphasize the emotion of the chorus.

It wasn't really noticable, but it did sound cool. If you are still unclear as to what I mean... I'm not talking about bass guitar bass; I'm talking about Rap song, synthetic Bass lines.

Do you guys know what I'm talking about?
If so, do you like it?

No fucking idea but that sounds awesome. Wish you could identify that song for me!

Could be the new System Of A Down song "B.Y.O.B.". Sounds like rap-metal without the suck. That's probably not it because its a bass guitar, but it sounds like its accented with synthetic bass.

Edit: Didn't see how old your post was, so this probably won't be it.

Here's a song that has "Metal Synth-Bass"

Lamb of God - One Gun

Make sure your bass is turned up.