brundlefly
I think he's saying that the security system captured the sound of the monitoring system during both recording and playback, and the audio on the security system sounds better when SONAR was recording. That should not happen.
 
Other than the added acoustic sound from the DI guitar and possibly sympathetic resonance on playback if input echo was left enabled, the only think I can think is that maybe the Track Gain is not 0dB. Gain doesn't affect live input so if the gain is set to attenuate, playback will be quieter than live input monitoring.

Yes, the security system DID capture the sound of the monitoring system during both recording and playback and that is what I'm listening to when I hear the differences.  I haven't looked to see if the gain is attenuated...'will do so tonight.

There are many variables here which we know nothing about.
 
First, try and define "sounds better". does "better" just mean louder?
 
What is the position of your video recorder in relation to your monitors? You could be picking up all manner of phase cancellations and reinforcements in fact I'd be amazed if you weren't.
 
If the video systems is relatively far away from your monitors, the room sound will come into play which will be picked up by the video mic.
 
How big is your studio? Is it treated? Do you have any bass trapping?
 
Unless there is a gain structure problem somewhere then personally I think you're chasing your tail on this one.