Latency Issues: Spark CDM | Mackie MCU Pro | Logic X

[mattplay]

I use the Mackie MCU Pro system (MCU, XT & C4) as a control surface for Logic X on OS X 10.9.

The MCU is connected via USB to my Mac. The XT & C4 extensions are both connected to the MCU's MIDI I/O via MIDI cables.

I also have Spark CDM 1.7.1 and a Roland A-49 keyboard both also connected via USB to my Mac.

I have Spark setup exactly as described in Arturia's document "tutorial spark 1.71 logic X.pdf"
- Created a MIDI Instrument in the environment/clicks & Ports
- connected Spark Private In to the MIDI Instrument
- Created a new bus in the IAC Driver named "Spark1 Midi OUT" within the OS X Audio/MIDI Utility.
- Set Spark preferences to “Send Midi from sequencer” and “Send Midi from Pads”

My issue is, when I open a Logic X project containing Spark as a plugin, the MCU control surface seems to work perfectly fine until I select the track containg Spark and the Spark controller "connects". After that, I get a big delay receiving feedback data on the MCU from Logic. As in, LEDs lighting etc. Further, I sometimes encounter delays with Spark. Like when hitting the pads, a latency with the sound.

Also, once Spark has connected. If I select a different track in Logic, and MIDI arm a different instrument, when I use Spark, it triggers Spark and the instrument on the selected track. I'd like to have the data not overlap with the devices.

I'd like to have my MCU control surfaces always control Logic X with no overlapping data from other devices if possible.
I'd like my Roland A-49 to control any MIDI armed track in my session (including Spark when that track is MIDI armed, if necessary)
I'd like Spark CDM to only control the Spark plugin with no data controlling any other instruments and also control Spark plugin even if a different instrument is MIDI armed.

Can someone more experienced with MIDI configuring tell me how I should optimize my communication in my MIDI studio. Using either the Audio/MIDI Utility or Logic X settings?

[mattplay]

Although the Arturia document says to enable "Send MIDI from sequencer" & "Send MIDI from Pads". I found that disabling both fixed most my problems I stated above.

However Im getting pretty bad latency from Spark when I hit a pad. Enough to not be able to drum live in my session. My Roland A49 has no latency controlling Spark or any other instrument in my session.

Any way I can resolve the Spark latency in Logic X?

Im also still getting the interference happening with my Mackie MCU products. I keep getting a long delay in the DAW feedback. It takes about 20 seconds for the MCU to reflect the DAW state. i.e., if I stop the playback... MCU counter still runs for 20 sec although Logic is stopped. If I select a track on the MCU, it selects in Logic fine, but takes 20 seconds for the indicator LED to turn on on the MCU.

If I disconnect the Spark plugin from the controller, the problems persist. If I power off the Spark controller. All latency in my MCU feedback is removed and they behave as normal.

If it helps Im running buffer size at 128. I have a Mac Pro 8-core w 64GB RAM and a MOTU 828mk3 interface.