Parallel compression and Scope latency?

[grappa]

Do devices in Scope have a latency?

I am playing with parallel compression on drums and am getting what appears to be comb filtering when mixing the original and compressed signals together?

If so can I just pop an identical insert on the original signal and disable or set so that it doesn't effect the signal?

Simon

[Lima]

AFAIK the latency issues occurs when 2 (or more) devices are loaded into 2 different DSP.
For this reason the big devices (as the big mixers for example) suffer of latency issue and latecy compensation is needed.

the mixers have the button "latency compensation" and a sample delay each channel (the big ones) but you can compensate everything using a sample delay. For example this freebe:



http://www.planetz.com/forums/viewtopic ... t=phasefix

[grappa]

Lima,

Thanks for the post.

I am using one of the big mixers so will give this a go.

Simon

[grappa]

Lima,

Thanks for the post.

I am using one of the big mixers so will give this a go.

Simon

[Lima]

[valis]

To get this to work effectively, I suggest sending a single 'test' signal down both signal paths when adjusting the phase/time alignment, and using the phasefix on the uncompressed signal path to add delay. You'll find that delay values introduced by a device's dsp loading are often in the range of 5-7ms or sometimes 13ms (if an STDM cable comes into play), this is of course not accounting for any overhead that exists in a device itself. Using a single sample retriggered that has a fair amount of low end and upper mid tends to help, for example a kick that's god a lot of 'beater' in it (or another sound layered in to increase midrange) and has had a bit trimmed off of the start so that it starts with a really 'clickly' attack (single sample to max amplitude). This also gives you the ability to record the result and check the time alignment, as phasing/flamming would look like 2 copies of the hit overlapping. A single cycle or 'impulse click' from min amplitude to max can also work (make it a few samples long in fact) or a reverse ramp from max to min, but I recommend with at least the former that you use headphones or just align visually by doing short bounces.

These hints are just off the top of my head, and are useful not just for aligning with phasefix but in general a good way to test phase alignment quickly when doing either digital or analog routing throughout your workspace.

[Lima]

thank you Valis! A very interesting and informative contribute.

I'll keep it in mind for the next mixing session