I got a musician to play in front of a pair of mics and fed those into the system. We then went back and forth between the audio room and the musician's room. This was to get an idea of the tonality and a step in creating a reference. The tricky bit was the room the musician was in was clearly audible in the listening room.A live event is a fleeting moment. What our brain stores as memories of a live event may not be sufficient to evaluate a system's performance.
If you have a good microphone, and a good pair of headphones, record your system, then compare that recording through headphones to the original. Then listen to your system again to check how different it sounds to your recording or the original on headphones, and so on. Be prepared to weep!
Or you can just listen to your system and ask yourself if you enjoy it.
Mine has always been Bruno Walter since I grew up with that. I'll have to look for a decent press of the Cluytens.What an entre to Beethoven's 6th Symphony, "The Pastorale". I can't resist - it's one of my very favorites. Here is true program music, illustrative music. B wrote a title at the beginning of each movement.
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My fav is Cluytens. HMV ASD 433