Ok, that I understand 
Again, my understanding (as a person who doesn’t use MACs) is that Logic is more efficient with certain plug-ins setups than Cubase. I just don’t know enough about it to say which ones may be causing you grief.
… even I do not know why, unfortunately
My problem is that I can not work with the buffer “so high”. Must be 64. Many musicians, when I did the mix, with all the vst, they want to record new tracks in the same project…
Fra’:
You can record live musicians into Cubase and avoid latency problem by utilizing the MOTU CueMix software that comes with the 2408. If you are the registered owner of the 2408, log in and download the latest MOTU Audio Installer:
File Name: MOTU_Audio_Installer-Mac-110806.zip
Type: driver
Date: 2011/08/09
Language: english
Version: 1.6.48575
Size: 18.0MB
Platform: Mac OSX
First bit of advice: if you are using Cubase’s Control Room monitoring system…turn it off. On a Mac, it easily adds a 15% increase on your CPUs headroom. Avoid it like the plague.
OK….
The idea is to use the CueMix software to provide a zero latency monitor or headphone mix to the musicians from the 2408 exclusively. You need to do some setup to get this to work well. If you are using Mics, you will need some sort of pre-amplification, as the 2408’s analog inputs are Line Level. You may also need a headphone amplifier/splitter if you are recording more than one musician at a time. Here’s a diagram of the basic analog I/O connections.
Open the CueMix control Panels and observe these settings. In this example, I’m bringing one microphone into the 2408’s #8 Analog Input via an external mic preamp. I am combining the mix from Cubase (via Outputs 1 & 2) and the 2408’s inputs (Analog Input 8) in CueMix and sending it out to a headphone amp from the 2408’s MainOuts.
Set record monitoring in Cubase to Manual Mode. This is the best way to avoid confusion and accidental “double monitoring”.
You adjust the mix playback from Cubase from Cubase’s own Output faders. There is no control in CueMix to do this if you are working exclusively with a single bank of analog I/O from the 2408.
You may find that there may be a level mismatch between the live tracking in CueMix and Cubase’s playback of the overdubs back into Cuemix. Simply set the Trim control on the overdubbed channels rather than raising the Track’s Fader (very top of the Cubase mixer. Hold Shift to adjust). This leaves you fader room for mixing. In this example, I’ve raised the Trim on Track 8 by 12dB. This way, there was no level shift between the live mic and the playback from Cubase. These may not be optimal settings for you, so feel free to experiment. I’m only showing you the general idea.
See if any of this helps your situation.
Thanks for taking the time you’ve spent to show me your procedure.
I will try this solution, although, I believe, I will not stay to use this software…
Thanks to all anyway…