Now, that's a reasonable response. Your Post 10 was a bit closer to rabid in its intensity:
On December 3, 2019 at 20:37, Brad Humphrey said...
WOW. It has been taught in audio classes for decades - DO NOT PUT 2 CENTER CHANNELS IN!!!
This causes comb filtering. Which is bad! If you think you don't hear a difference, you haven't demoed it (A/B) to yourself to hear.
... listen how the sound changes dramatically from seat to seat with 2 centers installed vs. 1. If you have an RTA, look at the comb effect it is creating to the response.
But above, you say
Amazingly it doesn't sound as bad as it looks on an RTA, which would have you believe response is completely destroyed.
You seem to de-emphasize how horrible the comb effect really is in comparison to the RTA display.