Who said “ flat freq response “ is the best?

Come on people. Speakers’ frequency response is almost always specified along the lines of 40 Hz to 16 kHz on axis + - 2dB. Their sensitivity is almost always specified along lines of 92 dB for 1 Watt at 1 meter. Just like stereo cartridges are usually specified along the lines of 15 Hz to 20 kHz +- 1dB.

@geoffkait 

For everyone,  geoff is accurate,  speakers publish their spec's with a frequency response and a variance within that response. 
Exceptionally flat speakers are normally rated Plus or Minus 1 db.  Anything that is typically more that plus or minus 3db is normally not considered audiophile,  although that certainly is not cast in stone. 
Today,  Many speakers are rated at a flat 2.83v input rather than 1 watt 1 meter.  For accuracy,  you need an accurate impedance, an accurate response curve and an accurate sensitivity rating. 

@ieales I've long had a mistrust of the press and regard it mostly as entertainment value only.

It would be interesting  to hear why you think phase has been largely ignored, and what did Heyser say about it? Thanks.

A further word on J Gordon Holt.  He conducted most of his listening evaluations utilizing master tapes which he made of acoustic classical performances.  And he seemed to posses a very good auditory memory.  That allowed him to make value judgements on how well given components came to reproducing those live creations.  How many reviewers today do anything similar?

I offer this since many readers may be too young to have much appreciation for Holt and what he meant to audio reviewing.  He cared about electrical performance, but his ears were the final arbiter.

Speakers posting their frequency response often are challenged by measurement (for example, every speaker reviewed in Stereophile), with peaks and valleys here and there all over their range. This might not mean much if the designer listened to them, which is generally the case. Also the frequency response noted by manufacturers is often utterly incorrect...I have a pair of very coherent, great sounding Silverine Preludes, which list the low end as -3db at 38hz, when at that point they're more likely -10db at least. My Klipsch Heresy IIIs are rated to around 58hz and that's pretty much exactly right...my subs take over at that point so it's all good.