posted on Sep, 17 2012 @ 04:04 PM
Let's break this down for the layman...
"Hz" and "KHz", or more precisely, Hertz and Kilohertz, are used to define or measure frequencies, usually associated with sounds or signals.
In the OP, the reference is in regard to sound. The measurements are displayed as "cycles per second".
Or, in more simple terms, as a speaker reproduces a signal, it must complete a cycle throughout it's range of movement. That can be described as a
vibration of the cone or diaphram, and is measured in Hz. Anything over 1,000 Hz is measured in KHz. The "K" standing for 1,000 Hz.
The average human ear can register sound, as in detect noise, from about 20 Hz, or 20 cycles per second, to about 20KHZ, or 20,000 cycles per
The reason that a high end speaker cabinet has multiple drivers in it is simple. A typical speaker is very in-efficient. A large speaker is great at
moving a lot of air, but it's cone is relatively heavy and it takes a lot of energy to complete a cycle. Because of this, many large speakers, called
woofers, can only reproduce lower frequencies, and are not physically capable of moving fast enough, to make higher pitched sounds.
Small speakers, typically called tweeters, can vibrate very quickly, and with very little energy required. But lack the surface area of the cone, to
produce the large waves needed for low frequencies.
Now sound can come in many forms, but it ALWAYS comes as a vibration. This vibration MUST have a medium or some form of matter, to move through. This
is why there is NO sound in space, or in a vacuum. No medium = No sound.
When we perceive sound, it most likely is through an eardrum, which vibrates at the same frequency as the sound we are subjecting it to, and
translates this information to our brain for processing. But, there are situations where our bodies can perceive sound, that didn't come from our
Ultrasound and Infrasound can sometimes be "felt" by the body, even though it is typically above or below our hearing threshold, above 20KHz or
Now, how this interacts with the mechanisms employed by our body and brain, to perceive sound is a bit of a mystery. And may be what the OP has been