[Spyro]

  This is not correct. Etymotic earphones are not flat, they are compensated to match a diffuse-field response with a slight treble reduction.

 
Etys have a treble REDUCTION?  This is even more bothersome.  Measurements aside most find the treble the accentuated part of the Ety experience.
 
What would this make the bass?  Enhanced?  Yikes!  Just not hearing it.

 

[tinyman392]

   
Etys have a treble REDUCTION?  This is even more bothersome.  Measurements aside most find the treble the accentuated part of the Ety experience.
 
What would this make the bass?  Enhanced?  Yikes!  Just not hearing it.

 
This only applies to the ER4S, ER4P, HFX, MCX, and ER6(i) I believe.  The ER4B and EtyKids X have been shown to stick almost exactly to the DF without any treble reduction.  With the original ER4B, Etymotic kept it strictly DF compensated, but found that the treble was to bright.  This was due to, allegedly, to a treble bump on recorded media, they stated about 5 dB bump in the treble.  They lowered that region to compensate, so technically, in correspondence to the DF, the majority of Etys have a treble reduction.  

 

[Spyro]

Wow, that's hard to imagine.  We all certainly hear or have heard about the loudness wars and boosted bass but I have NEVER heard about enhanced treble.

 

[tinyman392]

  Wow, that's hard to imagine.  We all certainly hear or have heard about the loudness wars and boosted bass but I have NEVER heard about enhanced treble.

 
That's what I read.  It was a long time ago, I'd have to find that original article.  I'm not sure if this was due to the loudness wars or not.