Real time printing vs. offline bouncing

[BKM]

I never used the "real time export" option that Cubase offers, because I thought that the only reason why you would want to use that is external gear - which I do not own. Turns out, there is a discussion online on whether real time printing can affect the quality of a purely ITB print, especially when you have complex time effects and lots of automation. I was never even aware that this might make a difference. I A/B'ed a mix this afternoon and formed an opinion, but I'd be interested to hear what you have to say before I'll throw it out there.

[Nabeel Ansari]

Some plug-ins don't work properly in offline bouncing in some DAW's. Kontakt has stability issues with changing tempos, and Omnisphere will actually omit the first note if it's right at the start.

It's not really much of an opinion; it's just knowing the tech. Pretty objective.

[Moseph]

Before I moved them to SSD, the EWQL Hollywood libraries -- if I used four mic positions at once -- couldn't stream from disk fast enough for an offline bounce. I'd have to do a realtime bounce and actually listen to the playback to make sure there weren't audio glitches.

[BKM]

Interesting. EZDrummer and the various Cubase VST instruments I'm using don't seem to have issues in that regard but I'll keep that in mind if I ever use more complex libraries. When A/B'ing an offline vs. real time export I had the feeling that the real time printed mix felt a bit punchier. But that could just be my brain tricking me.

[SnappleMan]

The thing is that you have to make sure your system is running smoothly as a whole so you don't get offline bouncing issues. Cubase is very good about it and there are very few issues with Kontakt if you are not maxing out your CPU meter. It comes down to how the DAW utilizes the CPU during the export process, Cubase usually takes a minute longer than Reaper does, but I get way more issues with Reaper so I have to re-render often.

 

If you hit F12 in Cubase you will get the VST Real Time Performance and CPU meter, there are two bars here, the top bar is the CPU meter that shows you how well your CPU is handling the load overall, the second bar is the Real Time Performance bar which shows how efficiently the entire system is running. If your CPU meter is maxing out then you simply cannot run that project well, and you can get export/bounce problems both real time and offline because offline bouncing depends almost entirely on your CPU (and offline bouncing will take a lot longer).

 

If the real time performance meter is maxing out or being erratic while the CPU meter is relatively low (CPU anywhere between 10-70%) it means that your OS is managing too many things (resource allocation for drivers, LAN, wifi, all kinds of programs) and the CPU has to handle too many other tasks before it can return to Cubase to process the audio. This is where the sample buffer comes in, if you increase the buffer size you let the CPU handle bigger chunks of Cubase's audio data, which gives you better real time performance, but at the cost of higher latency. Offline bouncing is fast because Cubase doesn't need to play the project back to you in real time, it can send huge chunks of the project to the CPU for processing and then wait to send more chunks as the CPU becomes available again, making it much faster than real time, so the real time peaks don't matter.

So the general rule is, if your CPU meter is OK, then you can do offline bouncing 99% of the time without issues regardless of the real time meter. If your real time performance meter is spiking then increase your buffer size and be careful about doing real time export, and make sure to double check that everything exported properly. The best way to handle external instruments has always been to record them into the project individually, and in the case with Kontakt and other AWFUL samplers like PLAY you can do the new "Bounce In Place" feature in Cubase 8 that does a fast spot bounce of that particular track (in virtually any output configuration you want, it's very very powerful), so that way you convert those MIDI/instrument tracks into Audio tracks automatically and your offline bounce process doesn't need to worry about it and can go quickly and smoothly.