Gearslutz.com - View Single Post - Plug-in phase drift w/ heavy processor loads - IOW: PLUG-INS SUCK!

SiliconAudioLab · 7th February 2006, 08:09 PM

What I’m talking about is the instability of plugs under varying and heavy processor loads and phase shifting from say a lead vocal or in my case often the actors/dialog tracks when stemming them out.

I'm telling you that depending on your load the plugs processing shifts in phase at certain frequencies. Slowly over time the phase will roll (during playback or course). You would think Digide$ign had compensated for this using their multiple DSP chips on the cards. But my theory is once they get taxed they too drift in accuracy. I mean look, the DSP of eq is all about subtle delay in macro levels at certain frequencies.

Instanciate a bunch of plugs until your computer throws the warning that CPU or TDM is near maxed. Then pull in a movie and see if things don't change.

It’s a slippery devil and it’s not freakin’ VERTIGO!

Once I get a spare millisecond second I’ll do more null testing myself. We should all be fully aware of how free running LFO’s in soft sytnths are not locked. I’m not including any soft synths or reverbs when this happens.

Start with a main vocal track.

I suggest is to instanciate many plugs in that one channel. Start w/ a focusrite plug then maybe channel strip or a ren vox compressor add a de-esser and maybe a throw in C4 for kicks in the main vocal track AND the other tracks.

Now add more plugs to other channels until a warning is thrown. Those tracks don’t have to have audio but even better if they do. Add those audio tracks WITH the extra plugs processing away. Now open a QT movie and see if things don’t start to slip with a null test.

I’ll use dozens and dozens of instances WITH Altiverb! Fine - take Altiverb out of mix by bypassing it but leave it instanciated.

I further suspect that even without a movie the problem exists at such a subtle level that when we are slamming big mixes we miss it.

The other way you could do this is to solo the vocal in/out with all those extra plugs in then null with them all removed completely (un-instanciated) except the main ones in the vocal track which need to be muted. Yes I'm factoring in plug processor delay (usually 3~7 milliseconds).

7th February 2006, 08:09 PM	#1
SiliconAudioLab Lives for gear Join Date: Nov 2004 Posts: 954	Plug-in phase drift w/ heavy processor loads - IOW: PLUG-INS SUCK! What I’m talking about is the instability of plugs under varying and heavy processor loads and phase shifting from say a lead vocal or in my case often the actors/dialog tracks when stemming them out. I'm telling you that depending on your load the plugs processing shifts in phase at certain frequencies. Slowly over time the phase will roll (during playback or course). You would think Digide$ign had compensated for this using their multiple DSP chips on the cards. But my theory is once they get taxed they too drift in accuracy. I mean look, the DSP of eq is all about subtle delay in macro levels at certain frequencies. Instanciate a bunch of plugs until your computer throws the warning that CPU or TDM is near maxed. Then pull in a movie and see if things don't change. It’s a slippery devil and it’s not freakin’ VERTIGO! Once I get a spare millisecond second I’ll do more null testing myself. We should all be fully aware of how free running LFO’s in soft sytnths are not locked. I’m not including any soft synths or reverbs when this happens. Start with a main vocal track. I suggest is to instanciate many plugs in that one channel. Start w/ a focusrite plug then maybe channel strip or a ren vox compressor add a de-esser and maybe a throw in C4 for kicks in the main vocal track AND the other tracks. Now add more plugs to other channels until a warning is thrown. Those tracks don’t have to have audio but even better if they do. Add those audio tracks WITH the extra plugs processing away. Now open a QT movie and see if things don’t start to slip with a null test. I’ll use dozens and dozens of instances WITH Altiverb! Fine - take Altiverb out of mix by bypassing it but leave it instanciated. I further suspect that even without a movie the problem exists at such a subtle level that when we are slamming big mixes we miss it. The other way you could do this is to solo the vocal in/out with all those extra plugs in then null with them all removed completely (un-instanciated) except the main ones in the vocal track which need to be muted. Yes I'm factoring in plug processor delay (usually 3~7 milliseconds). __________________ C'mon! "Soon, no one will have to DO anything."