On the feed to my sub, I turned the low bypass filter on to let only the only the lows in.

Question: Does the highs do anything in a sub at all? or does it just get in the way?

I don't hear the difference. But do hear a difference if I allow only highs in to the sub.

The goal is quality, instead of bone pounding base.

 

Well, the frequencies outside of the subs' range do get in the way. They can actually be harmful to the sub and the sound. Playing the frequencies above the sub's reccomended range will heat the coil due to the inability of the cone to move accordingly. Those same frequencies will also produce a humming because of the same problem. For a good clean sound, it is best to match speaker specs with the enclosure and crossover points. Sealed seems to be the enclosure of choice when it comes to quality sound systems....... Although, I prefer a ported enclosure, when it comes to auto sound systems (loud and clear).......

 

that actually is quality, i think your getting everything confused. if your speakers can be that loud its good, it just depends on how much gain you put on it.
Putting high freq is bad for subs.

 

also, your amp is less efficient when you are letting the highs in. this is because it is trying to amplify the complete frequency band rather than just the lower frequencies that you really want.

as for [(quality) != (bone pounding base)], i suppose it depends on what kind of music you listen to.