Surround Fold-down

[C]

I was RTFMing to find an answer to an unrelated question when I came across the section on Submixes (with reference to Drums).

I outlined a method that I hadn't previously considered for the process of downmixing 5.1 stems to a stereo bus by putting a send on the channels (L,C,R,ls,rs,LFE) and setting the send levels appropriately (0,-3,0,-6,-6,-6) I sent the LFE channel to a seperate bus (with Delay com on) first with a filter applied at 80Khz.

I then recorded this onto a Stereo track.

I set the same material up in our more traditional way (just routing the tracks straight to the stereo bus first and recorded the output again.

The first method (with the submix) seemed to be more open than the direct routing version. I can't understand why this would be the case but it is almost the same difference as doing a bounce-to-disk compared to a record-to-track.

Any thoughts? How do others do this process?

Ceri

[Frank Kruse]

maybe because of the filter (what ever type it was) at 80kHz?

I know you probably meant a 80Hz low-cut but why do you lowcut the LFE? Do you have full-range signals on your LFE? Did you apply the same filter in both methods?

Did you set the PAN correctly on the sends or were they straight mono-sends?

Try to invert one of the results and sum both and see if they null out. That will prove if they are actually different.

frank.

[Pete Gates]

I know you probably meant a 80Hz low-cut but why do you lowcut the LFE? Do you have full-range signals on your LFE?

If you're going to be super-picky you mean low-pass (or high-cut)

Lots of people I know put an LP filter on the LFE send so they can't get caught out with the 6-track being played incorrectly or someone downstream doing a fold-down without filtering. It does also mean they can send a full-range signal to the LFE (maybe in addition to LR)) to see what they can get out of it in the sub too.

[C]

I'll try the phase inversion.

C

[C]

I know you probably meant a 80Hz low-cut but why do you lowcut the LFE? Do you have full-range signals on your LFE?

It's just the way we've always done it.

Did you apply the same filter in both methods?

Yes.

The phase inversion results in some subby pops around the only material on the LFE channel (two gunshots). I'm trying to track down which version they are coming from.

Could be a delay compensation thing.

Ceri

[Frank Kruse]

If you're going to be super-picky you mean low-pass (or high-cut)

haha, nice one!

f.