In the last couple of weeks audiophiles have trekked to Florida and Canada to attend audio shows. Several after-show posts in various discussion boards mentioned that the SPL levels in
many of the rooms was LOUD.
Of course the reason the demos were loud was because the
ambient noise levels were so high that the demos had to be loud to be heard
over the din of everyone else’s demos! And while this may be an ideal
environment to hear what that pair of super-amps you’ve been eyeing sound like
when driven to clipping, it’s certainly less than an ideal listening
environment for most other critical listening criteria.
And what is an ideal listening environment? One of the most
important requirements is that it be quiet. Medium to high ambient background
noise robs music of much of its subtlety and power. Higher ambient levels also
requires turning up your system’s volume to compensate for the higher
background noise. This not only stresses your amplifiers, it also stresses your
Since the advent of SPL meters we have been able to measure the
ambient background noise levels of a room. My listening rooms register between
40 and 45 dB background noise level. In comparison, in some rooms at shows I’ve
measured ambient levels as high as 80 db. That’s a 40 dB difference. To get the
same signal to noise in that 80 dB ambient noise environment as in my 40 dB
ambient noise environment is virtually impossible. When I’m listening to music
with 95 dB peaks I still have 55 dB signal to room noise. In a demo room with
80 dB background noise you only have a 15 dB signal to noise ratio with this same 95 dB peak level, which is why I often measure more like 105 dB peaks at demos. But even that is only 25 dB signal to room background noise.
If you want a demonstration of how ambient noise affects your
listening room, try opening all your windows and listen to something. Set so
your peak levels are no higher than 90 db. Then close your windows and listen
again. You will hear far more detail, especially in the quieter passages.
One of the more profound and far-reaching improvements you can
make to your stereo system is to reduce the ambient background noise in your
Quiet is good.