Most pre-sub-out's are found on a.v reciver's. Or least back in the day. But some integrated amp's have them now. Does this mean they have some sort of bass management inside. or does using the sub out use the bass control next to the treble for sub only and not main speakers? When using a sub with this connection i mean. Cos my onkyo has the pre sub out. And i dont no if its directing the bass from my main speakers.