Although amplifier efficiency is good with this system, moving coil speakers operate at relatively low efficiency in the ultrasonic frequency region.

In its simplest form, an Audio frequency filter is typically designed to pass some frequency regions through attenuation while significantly attenuating others.

This technique has led to the suggestion that a low frequency dead region may be related to a loss of 40-50 dB.

Whereas, there may be a more obvious steeply sloping loss at high frequencies for a high frequency dead region.

As a result of the exposure, significant damage is observed in the high frequency region of cochlea.

It is a material which exhibits simultaneous negative values for permittivity, ε, and permeability, μ, in an overlapping frequency region.

This means the closely spaced harmonic resonances are likely to lie in the low frequency region and thus the response tends to be more uniform.

Also, the frequency response peakiness regularly seen in the high frequency region with moving coil drivers is absent.

He was determined to investigate the unexplored frequency region above 100 MHz.

It is often impractical and costly to switch to measurements within an entirely different frequency region.