Latency vs. Drop-Outs -- SOLVED

I'm hoping to find a solid resolution to this one: Trying to record vocals for a band this past weekend, I was seriously fighting latency vs. drop-outs. This was to the point we simply could not use the Echo abilities in Sonar and reverting back to using MOTU CueMix DSP for low-lantency monitoring (which unfortunately doesn't give us any compression).
 
My setup: Intel Z77 MB, Core i7-3770K, Kingston 16MB DDR3-1600Mhz RAM, Windows7 64, MOTU 24CoreI/O w/OP-AMP mods and BLA clock (I've tried internal clocking as well) (PCIe-424); Sonar X2a-64Bit. Latest version of CueMix DSP, latest drivers for MOTU unit and PCIe card. All updates applied to Windows 7, and no other programs running, no shared drivers. 
 
I set up latency Playback and Record to as low as 64, and froze ALL other tracks except busses (7 of them). With the DAW sitting idle and absolutely no affects on the vocal, I'm still getting about 100ms delay on feedback, which is not fun for the vocalist. I've tried using Record/Play Ahead caching, and have even gon through an exhaustive effort to perfectly synchronize the recorded vocal to the session (even ASIO drivers reported latency is still 30+ samples off). With the latency set to 64 for both, I get drop-outs even with all other tracks frozen.
 
So, with a fast and efficient system, little or no I/O in use, no CPU spikes, low DRAM usage, defragged drive, all plug-ins disabled or removed, I'm still hearing a slight delay from the Echo button in Sonar (up to 100ms). What would be a recommendation anyone has found here that you may have used to better latency that was not covered in the Reference guide? Cakewalk's recommendations got me close, but it's still not useable. Is there anything I can disable in Sonar that might improve this latency?
 
Thanks!

Keep in mind, this is not using MOTU's own low-latency monitoring, although we had to revert to that. Thanks for the response. I'm curious about the MB, though. This one is quite new.

There are some, yes, but not on the buss for Vocals. I tested disabling them anyway, to no avail.

I do use the Transient-Shaper on the snare from a Send. I also tried for test, disabling the compensation for plug-ins, but that only made things worse when I tried adding a single compressor to the vocal track (which is the main thing to accomplish). As a workaround to this, and the fact that MOTU didn't consider it useful to add FX to the CueMix DSP, we chose to let CueMix DSP return the monitored output to another pair of MOTU outputs where I routed the signal through a compressor, and then back into the headphone amp. It's a terribly old-school way of doing it, but worked like a charm. It's just a bit more work than I'd like to do for one simple task. Still, it may be easier than tackling latency, I'm not sure. hmmmm

Yeah, I forget about keystrokes. They're not always so obvious. I'm going to have more time this evening to mess around with it. 

Dappa1
Have you tried Studio One?

You mean, have I tested this scenario with another DAW as a reference to rule out Sonar being the culprit? Not yet, but I plan to take that to task if I've tackled some lower-hanging fruit first.

So, that's what's interesting: Even with the transport stopped, and not using any plug-ins on the Vocal buss, I'm still hearing 50-100ms latency in the Sonar X2 echo. What I have to rule out is whether I really have an issue in hardware, or if the Echo function is adding some delay.
 
To add, here's something of a buggy thing: Sometimes, after hitting record, then stop, with the Echo/Monitor button enabled, Echo stops. Sometimes I have to click Play, then Stop again to get the Echo back.

(1) I love 'em to death but I find my FabFilter plugins always cause me dropouts.
 
(2) Oddly, I haven't had unidentifiable  drop out problems for over a year or so but today - bloody awful. Only 24 audio tracks, no plugins and all I wanted to do was mix down in real time.  After trying the usual tweaks and getting nowhere I changed the Playback I/O Buffer size from 256 (where it's been for at least a year) to 512 and that seems to have solved it.  I'm still perturbed that this problem should rear its head now for no apparent reason.  

Virus scanners and Windows defender can add overhead that can cause dropouts. I always disable them and disable windows updates or disconnect from the network. If you are on a laptop with a battery, turn on presentation mode on Windows eight.

robert_e_bone
If your project has ANY plugins that are meant for post-tracking (mixing, mastering), then they will affect latency and cause dropouts.  There is a list floating around out there with exactly which plugins to avoid using during recording, but I don't have time to look for it at the moment.
 

 
Do you have any tips on finding said list? I would love to take a look at it.

bitflipper, I totally understand what you mean. I don't disagree with anything, so thanks for the reassurance of my own understanding/knowledge.
 
I've already compensated for latency in the DAW, which gets me synched up to the very sample, much better than even the ASIO self-testing can measure. I do expect some ever-so-slight latency, but certainly not 50+ms. Surely some people have measured much better than that. What's got me troubleshooting and providing workarounds is that as you mentioned, you use a much older machine, and can deal with the latency. So, it must not be quite that bad. My machine is less than 3 months old, with an iCore7 4/8 thread CPU, 16 Gigs RAM, SATA drive, new Intel MB with 2033Mhz backplane, and everything else in order up to what I know, which is fairly advanced.
 
CueMix DSP is the method we used, because it runs directly on the MOTU PCIe-424 card giving us a mere 3ms delay in feedback. This is very workable, since it allows me to change the feedback volume of the vocal while tracking is going on without causing Drop-Outs. So, this is what MOTU expects me to do, which works very well except, I can't use a compression plug-in (even a very fast one).
 
I just don't think I should be hearing the singer tell me, "Yeah, this is horrible. It's throwing me off". Maybe what's changed is a setting I didn't catch, or I don't really fully understand the right approach in latency-management.
 
gwitz, yeah, I do run BitDefender, but I disable it completely when we track. It's been an issue before when it would attempt to read the files Sonar was writing, which was seriously dumb on BitDefender's part. They don't even recognize a DVD movie before hijacking the DVD drive to scan it. heh

Brian good compact i glad you can take a plug in with out distortion i see your tolrencey level is coming back, hope you have checked your PLUG supply to make sure you computer is buffered with enough power so your computer doesnt seem sluggish!
 
Circuitry can play a big part in those drop outs you know.
 
Full power!
 
If not Studio One!

These plugins seem to be common causes of tracking latency: PC Concrete Limiter, LP-64 Multiband Compressor, LP-64 EQ and Perfect Space Reverb.
 
Bob Bone

Sidenote: I installed 32-bit Sonar alongside the 64-bit version, followed by the hotfix. Bad things happened with the Waves plug-ins. Lots of horrid static and inability to use them. I had to perform a bit of cleanups to correct this. I don't recommend trying to co-exist two Sonars 32/64bit on the same machine with Waves...