Equalizer in a Hi Fi system

The reason FLAT is not always what we want to hear hearkens back to my link earlier in this thread to the cello palette Levinson discussion regarding the fact that not all recordings are created equal 

Has anyone mentioned the elephant in the room? Eq’s destroy the phase relationships in the signal.  There can be rare times when the benefits outweigh the downside.  But most of the time, there’s a good reason why audiophiles abandoned eq’s decades ago.  And as several have mentioned, 2 sets of extra cables, with an extra box (and power supply) adds noise.  It’s all clearly audible even in a modest audiophile system.
  Less of a problem if it’s an all/digital signal chain. 

I use EQ software (APO 1.2.1) which is noiseless and to my ear the adjustments I made improve over all sound. I have an aluminum tweeter that can cause listening fatigue and a small ajustment eliminates the problem.

EQ. is useful as a tool not as the only solution , only a part of it ...

The phase relationship is potentially or actually compromised for a reason very deep not many understand well : human hearing was shaped and trained and biased in a certain way by evolution and live in a non-linear time domain of his own which cannot be reduced nor perfectly captured by the linear Fourier tools using abstract concepts which are linearly related (frequencies,amplitude and phase among others) and cannot  describe COMPLETELY  some aspects of concrete experienced  qualitative sound qualities which are perceived in REAL time in specific environment ...

It is why it was proven that hearing beat the theoretical Fourier uncertainty limit more than 10 times times for trained musicians ...

Then you are right there is a trade-off here using EQ. which can be a benefit for sure as any tool but also an impediment or a mask for other acoustic problems waiting to be solved otherwise ...

I then concur with this sentence :

Has anyone mentioned the elephant in the room? Eq’s destroy the phase relationships in the signal. There can be rare times when the benefits outweigh the downside.

The benefits for me outweigh these concerns. By the way, the noise with the EQ in with my gear is negligible, un noticeable. On a classical piano solo with EQ in and volume at 50% (very very loud), I don’t hear audible noise