1 Topic by FullScaleAV (edited by FullScaleAV 2024-10-24 16:49:38)

  • Registered: 2024-08-27
  • Posts: 6

Topic: Using loopback for mixbus processing to increase DAW performance a lot

Hi! I realized the other day that my Cubase projects initially choke when adding heavy processing on the mixbus. If you are like me and like to add processing/limiting on the mixbus during the production/mixing phase sometimes you could try this:

1. Send the mixbus to a pair of unused outputs on your RME-interface (e.g 5/6).
2. Activate loopback for these outputs (5/6)
3. Create a track in your DAW project with monitoring on and use these channels as input.
4. Send this channel straight out of your DAW to your main outputs.
5. Move any processing to this channel from the original mixbus.

Make sure every fader except your final monitor output is 0 dBFS. (Could there be any issues doing this with regards to clipping etc?)

This has given me sooo much more processing power. It really is crazy. I imagine that the DAW does not need to see it as a bus where all your channels have to go through but instead processes it as a normal track in parallel with the rest. You get a bit of additional latency but it is not at all noticable at higher buffer sizes.

  • waedi
  • DAW Mastermind
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  • From: Swiss Zürich
  • Registered: 2020-12-08
  • Posts: 4,522

Re: Using loopback for mixbus processing to increase DAW performance a lot

Interesting.
This seems to be a Cubase-unique-thing.
By logic it should be the opposite, the CPU-usage should increase not decrease as you add another track with active input.

Regarding clipping I don't see a problem, only feedback loop can be a danger as you mention parallel processing, I understand this as you would send back the new processed track into the master mixbus wich then goes thru Loopback...

M1-Sequoia, Madiface Pro, Digiface USB, Babyface silver and blue

3 Reply by FullScaleAV (edited by FullScaleAV 2024-10-24 18:20:02)

  • Registered: 2024-08-27
  • Posts: 6

Re: Using loopback for mixbus processing to increase DAW performance a lot

waedi wrote:

Interesting.
This seems to be a Cubase-unique-thing.
By logic it should be the opposite, the CPU-usage should increase not decrease as you add another track with active input.

Well, this is my logic: Doing this reduces the number of plugins that all tracks have to go through. So I’m thinking it should be helpful for other DAWs as well.

Now, ASIO guard might make it more or less effective in cubase but effectively it should make it as if your buffer size is bigger in relation to your plugins since you don’t cram your signal through a signal chain that is as CPU-intensive. You add an extra channel of heavy processing, but get rid of the bottle neck since the added channel is not part of the internal signal chain.

waedi wrote:

Regarding clipping I don't see a problem, only feedback loop can be a danger as you mention parallel processing, I understand this as you would send back the new processed track into the master mixbus wich then goes thru Loopback...

Yeah, I’d set this up with low volume when you make sure you are not creating a feedback loop.

I’d love to hear someone else try this out. I got a ton of extra CPU out of Cubase doing this. A project that would stutter, crackle and be quiet every now and then just doesn’t overload doing this (I’m sure I’ll hit the ceiling again, though)