Lets get down to the technical side of things, what is it actually doing? the attached below is with Post Anthem Room correction up to 200hz only. I only corrected response for bass and left the rest as it is.
the above is what i have measured, first the left speakers, then the right speakers, and finally , channel 3 (centre channel), where the signal is routed by the processor to L+R equally, in Green…
The left and right speakers have been level matched at MLP using a disc from dolby test tones with an spl meter. They measure 65db each, using a 20dbfs test tone with MV set at -20. first thing i have come to notice is that, the levels from phantom C increases by 2db, so Phantom C’s measured output at MLP is 67db. This is normal from the mains when both speakers sum in phase.
But notice above, as it goes past 10khz, the combined output is lowered, there is a gradual roll off about 5db down from 10khz to 14khz. (by the way, i can only hear details up to 14khz, beyond that i cant hear anything)
The above is a common response from speakers, when you play around with the degree of Toe In, the more you toe in, the higher the levels of upper frequencies and the more linear the amplitude response. This is because as you go higher up the frequencies, it is much directional compared to low frequencies where energy is less directional. so that makes perfect sense why the mic is reading a much lowered energy from the tweeters producing the phantom image >10khz. Because the tweeters from the centre image, does not fire directly at the listener position.
So you might have this question , why is the slope >10khz slopes down, but above you are saying it is 2bd louder? which is correct ? The 2db loudness, is derived when we do speaker level matching. When doing speaker level matching, the test tone generators produce energy from 500hz to 2khz. That is why when level matching the speakers for Phantom C, it is 2db louder. and that is why >10khz, it slopes downwards by 5db when it reaches 14khz. Speaker level matching always uses frequencies from these range
Listening test confirms i prefer a downward slope >10khz as compared to a linear target curve >10khz, the speakers sound less bright and fatiguing. I love how it sounds , naturally… without any need to EQ the mains and phantom centre.
How about headroom you ask ? At a 100hz crossover with the MA GX300, it takes up +3db more headroom from each speaker.
So at my place, with a 100hz crossover, i am not experiencing any distortion or notice any stress from the speakers at MV-8. i dont play that loud at MV-5 or reference type of levels. So thank god there, there is no stress from the mains so far.
Another interesting fact is, when blending a phantom centre to the subs, it must be noted that the first two LR speakers must first be time aligned. AFter which, one only needs to blend either the Left or Right speakers with the subs. And bang on, you will get the best blend immediately using ATR. If you measure channel 3 to time align the subs, it will be slightly out.
So bang on time and phased aligned for Phantom Centre with all subs , again adjusting 60cm distance to all subwoofers. (i have shared how to do it on the Anthem thread)
With L+R routing to centre, the timing is slightly off at 50cm distance. So that is incorrect way of blending the phantom centre.
Hope that helps, if you are keen to test this approach, go for it. You might actually like it