"MD" wrote in message
...
From text I sent to Sterophile

I have been a subscriber for about 15 years. In that time I have
learned, and tried to put in practice, good room treatment techniques. I
use test CD's and a sound meter to aid in placement and I treat all the
room hot spots like first order reflection, echo flutter and deaden the
area behind my head (my Triangle Celius speakers sounds their best in a
spot that forces me to the rear wall- I have an odd room). What confuses
me is the double speak on tone controls and equalizers as well as
exactly which test tones I should use when running the tests.

I, too, have found it strange that no one has written definitively (or
pontificated , on the subject of use of equalizers. There appears to be no
literature on how professionals have used these, if at all, in small room
environments.

I have no problem hearing the difference between equalized and unequalized
performance, and neither should you. Equalizers are not subtle in effect
when used to correct large anomalies. What I have found, which is not unique
to my own experience, is that equalizers more often than not make the sound
worse, rather than better. According to the literature, this is because the
sound which impacts the ear directly from the speaker is perceived
differently from reflected sound, but an SPL meter makes no distinction,
summing direct and reflected sound to produce the reading.

I have a large collection of fancy, parametric equalizers, but I have
largely abandoned their use, with one exception, which is a set of Acoustat
electrostatic panels that seem to benefit from a 2dB boost at 1.2kHz.
Ironically, these speakers interact little with the room; it appears to be
the direct sound that requires adjustment. Equalizers are best at slight
modifications of the direct (anechoic) response of a speaker, but even this
need has declined, as modern speakers have more even response than older
designs.

A ten band equalizer is useless for the purpose, since room anomalies align
on octave boundaries. You need a parametric eq., or at least a twenty band
unit.

If you have a good parametric eq, straight tones should be used. The warble
tones are useful to operators of eqs with lesser resolution, by reducing the
number of measurements required to achieve optimal adjustment.