Stereo to LCR atmos

[apple-q]

yes makes sense.

[myke2242]

Originally Posted by idris

I need to provide LCR atmos beds. They're predominantly for adding to existing mono location sound.
As I have no surround atmos in my library, I am planning something along the following lines:

Example ...
1min of LCR bed needed.
2min of stereo atmos FX available.
Solution ...
Use first min of FX track as LR.
Use one leg of the second min of FX track as C.

Does this make sense, or is there a better approach?

You may have some issues with that method. The C channel may not match your L & R channels. a example would be if there is a gust of wind. the gust would be in the L & R but not in the center. Your method could also have some phasing issues.

What i would do:

if you are using PT make a LCR (or 5.1, doesnt matter) BG master aux. send all BG track outputs to the BG master. Now make sure your are not panned hard L or R. now you have LCR BG's

[idris]

Myke, that's what I would have done myself, but I've been asked to supply a seperate centre, "so the centre level can be adjusted on its own fader.

[ErikG]

What is it for?
In general a lcr ambiance will be made up of a number of elements in editing. Not only of a single recording.

[myke2242]

Originally Posted by idris

Myke, that's what I would have done myself, but I've been asked to supply a seperate centre, "so the centre level can be adjusted on its own fader.

Yes what is this for. That is something normally the mixer would do. If you are just grouping elements for assembly i would still do the same thing.

use my example but switch out or add a LCR audio track in between. When you find a BG you like just re-record it as a LCR. it is a bit of extra work but you would had to listen to them anyways.

[myke2242]

Or you can do this... dup the stereo BG. process one of the sets as MS. The left channel will become your new Center channel. Discard the processed Right channel and add the Center to your unprocessed stereo BG's.

[ggegan]

Just take the left and right channels of the recording and bus both channels to a mono audio track and rerecord it, then use it for the center and keep the original stereo recording bussed hard left and right. You'll have to make sure that the sync is sample accurate.

Typically I don't bother doing that, I create a specific BG food group out of a number of different elements, some of which are stereo and some mono.

[nzl62]

Personally I tend to create atmos beds from several layers, some mono, some stereo and infrequently, 5.1 etc
That way you create whatever balance you want. In a typical atmos predub I will have anywhere from 2-4 mono up the centre for dx fill and the more active stuf LR or LR LsRs with some divergence to pull a bit into the centre or to tuck the spread in at the rears or whatever. I never try to do it all with one file

[Willeyh]

Originally Posted by idris

Myke, that's what I would have done myself, but I've been asked to supply a seperate centre, "so the centre level can be adjusted on its own fader.

Or just set up 2 auxes 1 for LR and one for C. Send The same signal to both then output both to your 5.0/1 atmos master bus. (Dont forget to turn down C volume from The LR AUX.)

Now you have a separate fader for C.

Why make it so difficult?

[danijel]

Originally Posted by myke2242

You may have some issues with that method. The C channel may not match your L & R channels. a example would be if there is a gust of wind. the gust would be in the L & R but not in the center. Your method could also have some phasing issues.

What i would do:

if you are using PT make a LCR (or 5.1, doesnt matter) BG master aux. send all BG track outputs to the BG master. Now make sure your are not panned hard L or R. now you have LCR BG's

Myke, your method will more likely produce phasing issues than the OP's. If there is any imperfection down the reproduction/downmix chain, you will have the same signal delayed by different amounts in different channels. That could make it sound only a little different in discreete reproduction, but make a wreck in downmix. I'm doing both methods myself, but as far as phasing issues, I don't see any problem with the OP's method.

[myke2242]

Originally Posted by danijel

Myke, your method will more likely produce phasing issues than the OP's. If there is any imperfection down the reproduction/downmix chain, you will have the same signal delayed by different amounts in different channels. That could make it sound only a little different in discreete reproduction, but make a wreck in downmix. I'm doing both methods myself, but as far as phasing issues, I don't see any problem with the OP's method.

i have never had a issue. sometimes there is very little difference between front and rears of 5.0 recordings although here we are talking about LCR so there will be no rear. Who is OP? btw i checked the MS method had no phase issues either.

[idris]

Thanks for all the input. I think I know which approach I'm going to take now.

[danijel]

Originally Posted by myke2242

i have never had a issue. sometimes there is very little difference between front and rears of 5.0 recordings although here we are talking about LCR so there will be no rear. Who is OP? btw i checked the MS method had no phase issues either.

I personally don't care if some playback system down the road will have inter-channel delay/phase issues, but I'm just saying that the OPs method is less likely to have phase issues..... 'OP' is short for 'original poster', or the person who started the thread.

[nzl62]

you have to be wary about phase issues in foldown to stereo LoRo where it can get phasey sounding or LtRt where you get a weird balance shift into surrounds due to decoding.
So check the foldowns and f they are cool you good to go. Personally I build LCR and 5.0 ambiences from multiple (mostly stereo and mono) elements - see above.

[charles maynes]

maximum de-correalation is always going to be best for any steering systems- I know in the past i have had to do fixes for material that went funny when doing Dolby Surround deliveries... BG's arent going to usually have specific panning in their elements- and if worse came to worse, you could use something like Anymix, UM226 or Spanner to fill in your dead zones.

[myke2242]

Originally Posted by danijel

I personally don't care if some playback system down the road will have inter-channel delay/phase issues, but I'm just saying that the OPs method is less likely to have phase issues..... 'OP' is short for 'original poster', or the person who started the thread.

I understand. we are kind of playing with fire on the decode. i would just worry that the elements being out of context and not matching enough. I wonder where this is going to be mixed...

[soundboy]

How 'bout routing the stereo out to a LCR track and using a little divergence to create your C? Re record it, and done. Anymix is nice too.

[maggot]

I use a Spanner on every track, no matter the format, and if I think a stereo or quad element needs to bleed into the C channel I just toe in a little using Spanner.

but as a few have said, you're always better to find more of the same and cut it for the center channel.
you can sync up wind gusts etc so it sounds like a real event.

justin