What describes the frequency spectrum into an amplifier that has higher amplitude at low frequencies?

The concept of a frequency spectrum that exhibits higher amplitude at low frequencies is described as having a negative tilt. This means that as you move to higher frequencies, the amplitude decreases, creating a slope that tilts downward.

In audio and amplification systems, this characteristic is often desired in certain applications, such as in bass-heavy music or when amplifying signals that are naturally rich in lower frequency content. The negative tilt allows for enhanced bass response, making the output sound fuller and more resonant in the lower frequency range.

The other choices pertain to different types of frequency responses. A flat response indicates that all frequencies are amplified equally, which does not apply to the scenario of varying amplitude. A positive tilt, in contrast, would imply an increase in amplitude at higher frequencies. A linear response suggests that the relationship between input and output is consistent across all frequencies, which again does not fit the description of higher amplitude at low frequencies. Thus, the negative tilt is the accurate representation of the described frequency spectrum behavior.