Yet Another Latency Issue Involving Audio through a 1620 into Logic 9

Question

Hi. Let me apologize in advance for my ignorance, and let me acknowledge that there are lots of tips on latency all over this and other sites.
I haven't found the answer despite some extensive looking.
I'm running Logic Studio / Logic 9 on a 32-bit only 2008 iMac.  I am using a Mackie Onyx 1620 [not 1620i] with Firewire InterfaceLogic as my audio interface.
I am tracking audio into a project with both MIDI tracks and Audio tracks.  I have established an audio loop as an augmented click track.
I have set latency to a low setting / buffer size in general preferences, and I have engaged "low latency" mode during audio recording.
I have no problem monitoring through my Mackie Onyx 1620 [not 1620i], with no audible latency or delay problem at all whilst tracking.
When I then play back the audio tracking, it is about 240 ticks off -- a dramatic latency problem.
The problem exists even where I have no other tracks beyond my audio loop, and where there are no effects on the audio loop/click track.
In other DAW setups, I've experienced latency in hearing my backing tracks and having an audible delay from latency in monitoring my input track.  This is effectively the reverse.
Any ideas?  And again, I am woefully under-educated in the area.  With your kind help, I intend to remedy that . . . .
Thanks very much.

Answer 1

Pancenter, thanks for responding and trying to help.
if so, you have a misunderstanding regarding latency.
I can promise you that you're right!
My understanding of latency in a nutshell: it is the small but perceptable delay [from "withholding" of signal] caused as a signal travels from point to point -- both (1) physical point-to-point (for example, from Mac processor to FW jack out on Mac through FW cable to FW jack in on interface, through cable out to monitor speakers or headphones); and
(2) processing point to point (from recorded audio track through multiple plug-ins on channels strip to bus or master out, through plug-ins on each of those).
I already know that I likely am wrong about this, or am at least incomplete.
Based on that understanding, the problem I'm experiencing defies latency as I understand it, and defies logic (no pun intended; I just mean it makes no sense, as I'll explain below).
What effects do you have on the master bus?
None.  I had none in the original project I described in my first query, and have none on a simplified experiment project I've conducted since (after reading your response).
If you are monitoring through the Mackie and NOT using Logic's software monitoring there is no need to set the Preferences/Audio/ I/O Buffer to a low value, set it to 256.  You also don't need to use Low Latency mode if you're monitoring through the Mackie.
Here, I think I understand, but am not sure. 
I am definitely monitoring through the Mackie in an absolute sense -- the returning signals from my DAW are coming in to the Mackie and (a) going out the 1620's headphone jack; (b) going out the 1620's master out to a Mackie Big Knob; and (c) going out the Big Knob's headphone jack, or to powered Mackie 824s.
[No, I'm not a Mackie devotee; I just happened across the gear at great prices, and thought I understood it.]
I don't think, though, that I'm "monitoring through the Mackie" as you intend it.  For my simple experiment, I established an audio drum track as a click track.  Each of the transients falls right on the metronome click/ beat location, so I know that it's "good."  I then plugged a Precision bass into the Mackie (channel one), with an audio track in Logic with "Input 1" as the input source. There are no plugins on the Precision track's channel strip.
Because the Mackie FW interface  on the 1620 sends post-gain but pre-fader, I was able to turn down all faders on the Mackie except the master out.  When muting the Precision channel strip in Logic, I hear NO Precision.  *Nothing from the Precision gets to the monitors if the faders are down and Logic is not sending signal.*  If I then "de-mute" the Precision in Logic, I hear signal through the master line in the Mackie 1620. 
In this setup, I assume I am not "monitoring through the Mackie," but I'm not sure.  I think that I'm "monitoring through Logic," and that's why I've engaged low-latency and set the preferences to minimize latency.
we need to establish your setup, how you're monitoring, and what effects are on the master bus. (if any)
In my simple experiment, with Logic set up to minimize latency, and with no plugins on the Logic master, I engaged "record" in Logic (only on the Precision track with no plugins), and I then played simple quarter notes on the Precision in time with the drumbeats in my Logic "clicktrack."  By playing simply like that, I confirmed that I am "in time" as far as my ears can perceive.  I then hit "Stop" in Logic.
Upon playback, my Precision is perceptably (about 240) ahead of the click track !
In my understanding of latency, at the worst the Precision should have been late because the Clicktrack would have been traveling through Logic's processing and down the lines to my monitors.
Again, thanks a ton for trying to help me out here.  I hope that this description makes it easier.