This is heavy and gives me a NEUS vibe, it would go off live. The intro is definitely intriguing too. Really cool track!

Dude this is awesome! I really love the sound of the chord plucks during the verse and the dynamic contrast throughout the track. I really love the complexity in the parts immediately before the drops. The only part I'd change, and this is just personal taste, would be giving the supersaws on the drop some defining characteristic that separates them from standard supersaws. All of the frequency and level automation on them is dope though.

While this doesn't necessarily answer your question, I believe this information is sort of relevant. Last week in my Physics of Sound and Music class my professor (who runs his own pro loudspeaker company) was discussing an issue in the industry. In reality, constructing a fantastic-sounding, flat speaker isn't that challenging (at least according to a man who does it all the time). The problem is companies will almost always compromise an amount of sound quality for aesthetics. This contributes to different brands having slightly altered sounds.
You also need to take into account your environment and room acoustics when you listened to these different speakers. If you aren't listening in the exact same setting and on speakers with the same dimension there's going to be some more variance.
Lastly, I know very little about speakers from different time periods but I'd assume speaker technology, consistent manufacturing, and general knowledge has just improved leading to cleaner mixes? Plus there's always audience preference. Perhaps speakers didn't have as prominent subwoofers in the 80's because there was very little music with emphasis on bass. Which would also tie into your "average speaker" theory because nobody would hear outside of a live setting in the first place.

I just submitted this to Illenium's remix competition. I don't expect to win but I'd love to share it and get some feedback! Thanks for listening, guys.

That's definitely a Sylenth pluck. It's just a saw wave with short decay/release and no sustain. The pluck comes from a mod envelope placed on a lowpass filter, with similar adsr settings to your amp envelope!

I figured it out in Serum from this, thank you guys! I was definitely over-thinking it.

So if this song reflects how you've been feeling then you've been feeling beautiful? Haha, but in all seriousness I really dig the drums/chord progression/unique sounds. The only recommendation I'd make is right around the 0:30-1:00 area it sounds a little muddy? It may just be the string samples you're using. Great work though! Emotional fuel creates the best songs.