"John Smith"

I compared my 1974 pair of ESL57s against a pair of newish TDL speakers
using a test CD with stepped tones and measured the output with a sound
level meter.


** Stepped tones are quite unsuitable for "in room" speaker testing.

Get yourself a CD with pink noise tracks divided into 1/3 octave bands -
like the "Denon Audio Technical CD, 38C39 7147 " It is not an expensive
one.


The high-frequency roll-off of the ESL57s was very noticable.
The higher tones (10kHz up) were there but the volume dropped off rapidly.


** Did you have the mic pointed at and directly on the central axis of the
ESL57 ?

What SPL meter did you use - not the cheap Radio-Shack one I hope ?

Did you set the meter to C weighting ?


What is the most likely cause of this?


** Your test procedure and gear.


BTW

I have been doing just such tests, with pink noise, on a pair of ESL63s
this week.




........ Phil