What strikes me is the passage about the SN76489 in the ColecoVision, which is superceded by a AY-3-8910 in the Super Game Module in order to play MSX music and sounds as intended. I can't recall if the Sega SG-1000 uses SN or AY, but I seem to remember the Sord M5 uses SN (among a number of other, far less similar systems).
Although I haven't investigated, does the Creativision also suffer from a SN76489 clocked too high so the really low notes can't be hit? I know the Commodore 16 and Plus/4 TED has a lower limit at 110 Hz, which is a bummer for musicians as A-1 isn't a particularly low note. Or maybe VTech did it right? Other SN-based machines could be used for comparison, if now the chip itself can produce lower notes given a lower input frequency.When ColecoVision was launched in U.S. in 1982, was it an early "unfinished" MSX-based machine. Right after came the first "finished" SpectraVideo 318 and the successor MSX1. So practically all these "finished" MSX games from the 80's can now be translated back to ColecoVision with very few changes. And that's also include the games from Sega SG-1000.
But the sound chip and the RAM were not the same, and here comes the new Super Game Module. The top sound is coming from the more sophisticated sound chip: AY-3-8910, the same used with almost all MSX computers and many other computers and arcade machines from the 80s. The AY-3-8910 is a step forward from Coleco's own sound chip, namely SN 76489.
The people who created the ColecoVision made a bad mistake with the CV PSG. The CV PSG isn’t bad at all, but they clocked it too high. Because of that, we are limited to frequencies above 110 Hz, which means, that deep bass sounds can not be produced by the CV.
So that is why the Space Invaders Collection marching sound in SIC isn’t as deep as you remembered it, or some music stuff sounds so “high” in the frequency range. The new PSG corrects that, and goes beyond what the Texas CV PSG can do, with volume envelope and better noise generator. The AY helps by offering a wider frequency range and by increasing the total number of channels available.
Additionally both PSGs can be used simultaneously, and all sound is routed to the RF output. (A/V mods can still work if the sound source is taken from the output of the sound mix, just before the RF input).