I can do that with some of my equipment, too.
... but I gather that yours is mostly, more modern.
Not all of it. My garage system has a Sensurround subwoofer thingy that is round 35 years old now.
Technology which enables propagation of subaudible wavelengths has not changed in theory since the mid twenties. Some of the hardware is better, but "the song remains the same."
I would expect that a high quality reproduction system from thirty five years ago would sound as good today as it ever could, if it is in mechanically good condition.
My coolest/best sounding subwoofer system is driven by four, JBL E140 bass instrument drivers (circa 1976) which have been converted to produce lower frequency resonances and move a bit more air than stock. (yes, they are customised) They fucking kick ass!
Old speakers are fine! I have not seen anything modern that can even approach the quality of sounds I can create without spending many thousands of dollars.
I am peripherally jealous, in some ways.
I would love to have cinema-style digi things .....
Only the fairly modern ones have the potential to sound good in anything but cinemas with cinema speakers. Well, there have been exceptions, notably the Dolby processors of old, but there's a lot of junk out there, too.
This is an area I would enjoy exploring more.
I have only seen modern digital hardware I would assess as junk, but I know better equipment exists.
I had a Dolby Digital Surround processor that I experimented with in the early nineties, but it was a leased item and I could not afford to buy it outright at the time. I was not able to take my system (which was designed around the severe requirements of live rock performance) in that direction then, but it opened my eyes and my ears to the possibilities.
OH, interestingly, the "Demo CD" that accompanied the DDS (if I remember correctly, it wasn't called DDS, though) unit featured, none other than Ostein Seivag, (sorry, I doubt if I have the spelling correct) a well respected (these days, not then) Swedish New Age genre musician.