Oscilloscope Monitoring | eSSB | SSB | AM Audio Modulation, Amplifier and System Linearity
The only 'splatter' that is possible - that I am aware of - would be having the ALC too wide open on SSB mode. A radio can TX as wide as the filtering will allow, and can even be byassed altogether.
Running audio gear for best results isn't as simple as one might think. Ask someone who worked in a recording studio. Oftentimes, less is more. Guys go to school how to do that, and end up taking in years of experience before they can even be considered to be a real 'pro'. If equalization is the issue; then a mic better suited is chosen, rather than EQing both pre and post recording. Compression is real art form, and is often the one processor that is least understood and often done incorrectly.
The complaints made by some Hams is a 'sour grapes' argument concerning eSSB. They don't understand it, it is new and therefore threatening, and are unwilling to understand its place as valid experimentation. Because 'Joe Blow told me so". The proof of this is their claim that the amateur is 'attempting to have a commercial broadcast station'. That is the tip off, not because that would be impossible to do, but rather because that is not the goal. That would violate amateur rules of proper freq use.
Besides the presence of filters in a radio, the engineers have also added caps to the mic audio circuit that cause the mic freq to begin the process of shutting off before it reaches the filter for both the low and high freqs. This helps the filter have a better shut-off slope when it kicks in. The reason to inject directly into the balanced modulator is to avoid all of that. The other option would be to change the values of those caps, and that can also be done. Been there, done that.
Having run a FlexRadio SDR-1000 ('my fave'), I can tell you that the filtering in it is all done digitally. There is no such distortion because it is running 20k wide to another radio. The PA section cannot tell the difference, IIRC. The problem is found in the 'other radio' because it cannot hear all of what the other radio is putting out. No skin off of anyone's nose, except that running 20k wide will take up too much bandwidth under the rules is all.
Just because some radio operators have made mistakes trying to do eSSB, it does not preclude that it cannot be done correctly. Neither is it necessary to have a SDR-1000 to do it right. There are plenty of eSSBers that have YouTube videos that prove conclusively that it can in fact be done right. It is fun, and it makes the hobby more interesting than it was ten years ago - IMO.