Putting stereo insert on L & R channels of 5.1 bus

[amathie]

A Pro Tools nubie here so thanks for any suggestions or help you can offer.

I would like to process just the Left and Right channels of a Surround 5.1 bus. I have read the relevant parts of the reference manual and it seems like there is no way to add a stereo insert on a 5.1 output or bus. I can't quite think of a tidy way to make this happen by splitting the L and R channels off from a 5.1 signal and rejoining them. Does anyone have a good way of doing this?

[albee1952]

How many insert paths are available in your IO setup? Could you insert on all paths(6 for a 5.1 mix) and simply hard-wire the rest, while your L&R actually go thru external hardware(IOW, the rest of the paths go thru output>input and right back in with no processing)? Shot in the dark as I don't do much surround work here

[joachim]

If the plugin to be inserted has a multi-mono version, insert that, unlink the channels, click L and R in the linking display, leave C Ls Rs and Lfe with a neutral setting.
Or : in the 5.1 bus, create a stereo sub-path of L and R. Create a stereo master fader with that stereo bus as input, stereo insert there.

[amathie]

@ albee1952
Thanks for the idea. If I've understood you correctly you are suggesting using a 5.1 hardware insert and just processing the L & R channels. This would be great if I could use hardware, but the processing I'm trying to do only exists in software and only works as a stereo pair. I could however use this idea to return the stereo pair back to a stereo Aux Input on which my processing would be added as an insert, before routing the output to the stereo subpath of a final 5.1 bus. Hmmm...!

[amathie]

Originally Posted by joachim

If the plugin to be inserted has a multi-mono version, insert that, unlink the channels, click L and R in the linking display, leave C Ls Rs and Lfe with a neutral setting.
Or : in the 5.1 bus, create a stereo sub-path of L and R. Create a stereo master fader with that stereo bus as input, stereo insert there.

@ Joachim
Thanks for the ideas. I have to use stereo software processing so the multi-mono approach won't work. Actually, at the risk of making this more complicated, I also want to treat the rear stereo pair separately with software stereo processing.
Your idea of subpaths or perhaps sends seems promising. I don't know if I can create a subpath or stereo send of just the Ls and Rs channels. I'll do some experimenting!

[joachim]

Originally Posted by amathie

I don't know if I can create a subpath or stereo send of just the Ls and Rs channels.

Subpath creation like in the picture. And then 2 master fader.

[JFreak]

Long story short, you can do:

- obviously 5.1 insert on 5.1 track, bypassing the channels you don't want to process
- split your stuff to sub mixes and process what you want the way you need to
- work on multi mono if the task is very complicated

...but you cannot insert a LR plugin on 5.1 track and have it return a 5.1 material after the insert. You can up mix mono to greater-than-stereo or down mix surround material to LCR/LR/MONO but it just doesn't work like you have an insert plugin and it would magically only process LR "for stereo processing"

[Rich Breen]

You might be able to build it with one of these:
http://www.bluecataudio.com/Products/Product_PatchWork/
http://ddmf.eu/metaplugin-chainer-vs...s-aax-wrapper/

[amathie]

Hi Joachim,

That's brilliant! It works like a charm.

SUMMARY OF ISSUE AND SOLUTION FOR FUTURE REFERENCE:

BACKGROUND: I want to be able to process the front stereo pair (L and R) and/or the rear stereo pair (Ls and Rs) of a 5.1 mix, independently from the rest of the channels, with stereo processing. It is not possible to achieve this using an insert on the 5.1 channel which must be either a 5.1 or multi-mono plugin.

METHOD USED:
Take the 5.1 aux (the channels of which you want to process independently) and send it to another 5.1 aux using a 5.1 bus. Create subpaths of this bus corresponding to the channels you want to selectively process. So, for example, I created two stereo subpaths, the first for the L and R channels and the second for the Ls and Rs channels. Next create a Master fader and allocate it to the subpath you want. The Master fader now allows you to insert a stereo plugin to process that stereo subpath independently.

COMMENT:
In effect, rather than putting a plugin insert on a 5.1 channel strip, you are creating inserts on selective subpaths of a 5.1 bus between two 5.1 auxes. These inserts are provided by Master Faders. This works really well and allows a lot of flexibility.
Being new to Pro Tools I thought that a Master Fader, with its post fader inserts, should only really be used on an output. In this use, it is ACTING AS AN INSERT in the subpath of the bus between the two aux channels.

[joachim]

Originally Posted by amathie

It works like a charm.

Good to hear, that this works for you.
Different situations might involve methods mentioned in other posts.