the dynamic load of the drivers and crossover will cause massive changes in the impedance of the speaker system. The drivers shift all over the map, thousands of times per second.
As high as a few hundred ohms, and as low as into almost negative numbers.
This is reacting against the Class D output filter.
This means the filter and the driver combination, is all over the map in their effectiveness of blocking or dealing with the amplifier’s output.
The trick is that the drivers are not static in their impedance value.
Which in turn, causes the effectiveness and the nature of the output filter to be all over the map.
If one measures with low values of signal and/or a sine wave, none of this real world stuff will be visible in the measurements.
I’m not taking umbrage with any side of the debate on sound quality, in this. I’m just noting the reality about the class D output filter shifting all over the map, thousands of times per second, in it’s basic effectiveness, in any real world scenario. almost as if the filter was designed in a static formula/static load scenario. Like a single frequency and wave shape of output and single unchanging load.
The real world is all over the map and dynamic as hell.
Thus, class D output filters as they stand today = Wrong. Incomplete. Not correct. I don't have a solution, but I did see the problem, in the very first few seconds where I saw a class D amplifier for the first time. I do have some ideas, though.
