Thanks, James. This one is obviously a known issue with many but I knew there were a LOT of people who not only weren't aware but don't really understand what we mean when we say "comb filtering" and "off-axis"... Those are the folks I wanted to make this video for. I'm happy to hear that it's helpful.
Very good presentation Erin.
I have railed against horizontal MTMs for years. They are unacceptable. The best audio and cosmetic solution is coaxial designs. Although in the small condo we had that was a secondary home, I used a full ranger and that worked well.
There is a problem with three ways though, which concerns the polarity of the mid in a three way. Because of lobing issues, you really want an even order crossover in a center. So usually you will have second order crossover, as fourth order has too many, and too large components to fit in easily as well as significant added cost.
The issue comes, when the left and right are two ways and the center a three way. In order to avoid a null at crossover the polarity of the mid is often reversed. This then puts the mid out of phase with the the woofers of the left and right speakers.
I ran into this problem with my in wall design for out great room. Luckily the null was very narrow. Accepting the null was audibly far superior to the out of phase condition between the center mid and the left and right speakers.
I suspect people have selected three way centers, and wondered why results are not what they expected when the mains are two way, or 2.5 way.
I should have anticipated this problem, but I admit I overlooked it, but the problem hit me four square as soon as I listened to the set up.