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 ears.
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 listening room.
Quiet is good.