Avoiding the half height bad spot

When your monitor height is at half of the ceiling height, we know that's bad. How much is enough to avoid this? Is two inches below half way enough? And do you measure from the mid point of the speaker cabinet

It depends on what frequency you are worried about, and your overall room design, dimensions, shape and suchlike. Moving down two inches if you have 20 foot ceilings is not going to change much. Moving down two inches if you have 7 foot ceilings can change quite a bit more. It's more a matter of percentages, not do much inches (although inches also come into it). All things related to your speaker should be referenced to the acoustic axis of the speaker, which should be identified in the documentation that came with it. Or ask the manufacturer. If you can't find out, then it will be somewhere on the imaginary line joining the center of the woofer to the center of the tweeter, and much closer to the tweeter. Some folks suggest using the center of the tweeter, but in reality it will be a bit off from that, towards the woofer. - Stuart -

Thanks Stuart , my ceiling will Be 7 ft 10 inches . So flush mounted at 1.2 mtrs, a couple of inches or so off half way will have to do. Hopefully it's enough.