Your terminology is confusing. MRC does not set this restriction. Bass management does.

Basically for discrete formats if a speaker is full size it will not take it's bass away.

But in Logic (not just Tv-Logic though) any time the ceneter is derived (from 2 channels for any non music format e.g. Prologic, THX, PLII, TV-Logic) and not discrete it will send that bass to the sub.

I guess they figure they have some derived bass that could go anywhere so they assume the best place is the sub. I'm not sure why they restrict it or not allow you to override it.

Since there is no LFE in "2 channel logic" if it didn't route the center bass to the sub, the sub would not run at all.

If you look under Music Tab and switch the Bass Flow Diagram to 2-Channel (with 3 Large Fronts and Sub) the sub is not used at all. For some reason they do let you override center size on 2-Channel Music. I guess they assume you'd want the impact on the movie.

- Fiddler (IMHO)

If you think listening to music is fun, try learning an instrument.
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