Equalizer in a Hi Fi system

Thanks, my friend. Great insights. 

So post production, what’s the best way to implement say a SPL PQ plug in for digital EQ?  You’d have to use a computer to do it?  And dedicated outboard DACs are more high fidelity, yes?  In other words, in the home stereo setting you are better off doing the EQ post conversion in the analog domain?  Then you can use whatever high end streamer and dac you choose?  Which sound better anyway?

Boils down to dedicated streamer vs computer serving code. Easier to get highest fidelity from former than latter. Probably best to stick to, in this example, hardware SPL PQ vs plug-in for home playback. I’d also be willing to bet bigger broader tonal boosts like air band better done with analog hardware than same equalizer via plug-in digitally. Miro, you seem to indicate this for playback 

On extension, I’m guessing the best fidelity post production playback digital EQ would indeed be something like @mijostyn ’s DEQX Preamp. Because it’s a dedicated audio piece optimized for highest fidelity playback. Well, I still want try DEQX, @mijostyn , or hear it in a showroom. Let me know when I can hear that. 

Just a quick update - I managed to find an output cable XLR to RCA that works perfectly. Just a cheapo from BlueJean Cables.The way it's wired is pin 1 to ground, pin 2 to signal, pin 3 floating(unconnected). Being pretty ignorant about electrical circuits and how and why they work, I did a lot of reading and also came across an illustrated chart that explained the many ways to wire and convert patch cables from one format to another.The adapters and cables I tried previously used both pin 1 and 3 for ground which is how the input side is usually wired when going from RCA to XLR and often works for the output side but not always. Apologies for my other post where I said pin1 was for signal,too late to edit.So now I can give the API unit a try and see how that goes. tlcocks gave me some interesting suggestions of other eqs to check out that are very well reviewed and would be fun to play with, but I'm sticking with simplicity for now.I just want to correct a tiny bit with some overlap for smoothing.