What single change made the biggest improvement in your system?

[ciprian pop]

The biggest improvement (apart from the speakers and positioning) was the filters obtained after measuring and calibrating with GSonic Reference. The results are stunning!

 

[JohnnyNG]

Tough (and probably inaccurate) to narrow down to just one change but getting rid of all passive crossovers and going with a full active setup was a biggie. Dirac Live below 500Hz was also huge if I may add a second.

 

[Petrushka]

Cheap storage has made the biggest difference to me.

I had a good system in 1969. Dynaco, AR. But digital has removed clicks and pops, and made handling of media issues nonexistent. Streaming has opened up a vast library that was entirely unaffordable.

My CD collection is now on USB drives, multiple copies for backup.

I have had Mozart playing for several days. All of it, 170 CDs, on a single Sonos playlist. That was a hold my beer moment, and I will get around to making smaller, more rational lists. The interesting thing is, it is possible.

 

[HDavidson]

measurement microphone + REW + DSP filters. The other things are minimal.

 

[Tell]

LOUDNESS Compensation (JRiver Media Center).

https://wiki.jriver.com/index.php/Volume#Loudness

I've been curious about loudness compensation for years and have had small tries with it using EQAPO but nothing that I kept using for some reason, but now with the DSPi development here on ASR I've now used it for a while in my main system and tbh it really is a game changer for every day usage since you get the "full" sound no matter where the volume is dialed to.
So yeah I've already answered earlier in the thread that the upgrade to a MiniDSPand a UMIK1 around ten years ago is my biggest upgrade, but in the last few years I'd say that loudness compensation has been the biggest one