Behringer DDX3216 Phase Invert Bass Cut

[Phoebus1966]

Hi everyone using the Behringer DDX3216.

If you do not have it in front of you please ignore this thread.

My issue is when I invert phase I notice a difference in sound coloration. Definitely there's a bass cut.

This is odd because a phase inversion should not be audible at all.

The signal is mono fed. 1 line. Not stereo. So that's out of the way.

The mixer is FIRST loaded with DEFAULT state. So that's out of the way too.

One line.
Mono.
That's it.

Please do a phase inversion on a single channel single signal on your DDX3216 and let me know if you also notice a bass cut and difference. Thx! (I suspect DSP cannot handle low frequencies but that's do darn odd because it's just an inversion: 'x -1' and nothing complicated).

[Phoebus1966]

I have further experimented by doing the same with a Yamaha AW4416 and to my surprize I hear the same effect. I must say I am using as a sound source the Yamaha TX81Z FM synth LatelyBass preset in an arppegio loop. The signal is unbalanced but I wouldn't know immediately how that would effect the situation if it were a balanced signal, really.

On the Yamaha AW4432 you can route the exact same signal to multiple channels which the DDX cannot do. That way, by inverting the phase of one channel, I could check if both cancel each other in the mix and yes they do. This means this is proof both signals only differ in phase and nothing else.

So it seams with low frequencies a phase inversion can be recognised by hearing as absolutely different, this means not only at the moment of phase switching or in reference to an simultaneously sounding non-inverted signal.

If anyone can explain the physiology of this just go ahead.