It is pixel based.

​Not sure how well the Speco works but other pixel based motion detection allows you to set the sensitivity and mask areas as well.
​I usually setup the motion detection to be very sensitive, so it is recording often. Better to have more, than to not have enough and miss needed footage.

​If you are setting up email or push notifications, then you usually don't want to go that route - you will get massive false alarms all the time. Or if you set it to low and mask off to much, will miss needed notifications.

​Better to use a separate motion sensor for these situations, triggered back to the DVR.