Thanks for trying to assist.
Yes I have followed the recommended settings for an aggregate device with 2 pcie cards. However results are the same if I use the aggregate device, or just use one interface with the other disconnected, ie not in aggregate.
So that is not the problem as far as i can tell.
For the loopback test, i used the project from the steinberg ftp. I’m not sure what you find incomprehensible about this, so please let me know what further information you need.
I routed outputs 1+2 to inputs 1+2 of my interface using the RME totalmix software.
Recording the outputs 1+2 back into inputs 1+2 results in the recording appearing 90 samples early.
Therefore I must adjust recording offset by -90 samples in order to get the recording to line up with the original.
Leaving it at 0 samples as you suggested always results in a recording being 90 samples early.
Note… this is before using any external effects. No plugins of any kind were used in this baseline loopback test.
So that is the first issue… there is a “negative delay” when recording and this is reported by a simple loopback test.
Now for the external FX.
They are definitely connected correctly because i can send audio out and receive it back having been processed.
If i right click and choose “check user delay” in the vst connections window, the ping is sent and i get a delay of 1.08ms.
However… when I insert the external fx plugin on a track, and click the ping button, the delay slider returns to 0ms.
Now, using the same loopback test, if I insert my external effect plugin and record the output, the audio is recorded 13 samples early. If i adjust the record delay compensation (already on -90) to -103 samples, the recording is aligned with the original. Every time I add a new external effect plugin to the original track, it creates a further -13 sample delay which I must compensate for in the recording offset.
so 2 things are happening here.
1.) there is a recording offset of -90 samples which i have to manually compensate for, even before using external effects.
2.) the external effect plugin does not ping correctly, it always reports 0ms (although the vst connections setup is able to measure a ping of 1.08ms) - even though my connections are in place, and i can send and receive audio to and from my outboard effects.
I hope i was able to explain that clearly. Essentially delay compensation is not working for me, and I have to manually measure and compensate. As i said, using the external i/o in logic 9 correctly reports the -13 sample delay on external effects. So in logic i simply set the recording offset to 90 samples, and the logic i/o plugin is able to compensate for the -13 sample offset without me having to adjust recording delay each time, unlike cubase.