Hi guys. Just wanted to tell this story. It seems there is a new wave of 80's synth pop inspired music coming along, such as
Lazerhawk and
Com Truise. I quite like it. So, inspired by these, I made
a song. I got feedback from two places: the first was a soundcloud comment, which you can see for yourself ("I could totally see this song in one of those old amiga games

"), and the other was from some friends I played it for IRL. It was something along the lines of "Reminds me of old synth music" or something like that.
Later, I was listening to Lazerhawk, and I realized why I got those two comments - I never added reverb to any of the MIDI tracks in the song. Then I realized that reverb and other post-processing sound filters separate retro sound from a more immersed modern sound. And that is because old sound synths, such as the Yamaha FM chips and the other retro sound chips, don't have reverb or echo or anyhting. Some songs could simulate echo by doubling the notes, playing one note on one channel, then a few ms later, the same note on another channel, so it sounds like there's an echo. That would be good for a bit of immersion, but the sound would still be metallic because there's no lowpass filter cutoff.
So my conclusions are - if you want to get a retro sound, avoid reverb and other effects, just use plain FM synthesis or even square wave, and if you want to get a full, immersed and expressive sound, start adding reverb, lowpass filters and other effects. Also, if you're designing some sort of sound generator, maybe a MIDI synth, be sure to include some effects in it, at least a lowpass.
What do you guys think?