just to clarify, theres no such thing as overkill

If you turn the gain down/sub control down from the head unit and are still able to hear the treble at the same amount of DB or at least where the treble is audible and not overpowered by the bass, then that's fine.

I don't condone ghetto bass whatsoever.

define ghetto bass haha. if i were to crank my radio with my sub/amp combo, i can shake a few windows and such. but my speakers are amplified which will can keep up enough to not be inaudible

Ghetto bass, to me, is where someone adds 1000+ w rms but doesn't add any components or 2-ways or tweeters to the mix.

I sometimes wonder if the people I "feel" from a ways away just tore out the stock mids/highs altogether.