Editing Low-frequency effects (section)

== Types ==

=== Low-pitched musical arts ===
LFEs include both low-pitched musical notes and low-pitched sound effects. The musical [[soundtrack]] for many films includes bass instruments that produce very low notes. Until the 1970s, most of the low-pitched instruments were natural, acoustic instruments, such as the [[double bass]] or the [[pipe organ]]'s [[pedal keyboard]]. After the 1980s, film scores increasingly used synthesized instruments, including [[synthesizer bass|synth bass]] keyboards, which incorporated very low-pitched notes.

=== Sound effects ===
The most challenging sounds to reproduce from a sound engineering standpoint are usually the extremely low-pitched [[sound effects]] in the 20&nbsp;Hz range, such as those used to simulate the sound of an explosion, earthquake, a rocket launch, or submarine depth charges.<ref name=SubwooferU571></ref> The human ear is not very sensitive to sounds at these low frequencies, so it takes a tremendous amount of amplification for the human ear to hear them. Further, sounds at these frequencies are more felt in the body, rather than heard. As well, since they are sound effects, they may have a longer duration or sustain than many low-pitched musical notes, which makes them harder to reproduce accurately.{{citation needed|date=May 2011}}

It is a formidable challenge for an amplifier, subwoofer speakers, and cabinet to reproduce these sound effects at a high volume without encountering problems such as power amplifier [[Clipping (audio)|clipping]] (distortion), unwanted rattle or resonance in the wooden cabinet, or excessive "chuffing" sounds from the [[bass reflex]] vent (if a vent or port is used in the cabinet). Sound recording magazines sometimes use the loud, rumbling sound effects simulating the sound of the submarine depth charges which were used in the World War II film ''[[U-571 (film)|U-571]]'' (2000) to test the accuracy of subwoofer systems.<ref name=SubwooferU571>{{cite web |url=https://www.soundandvision.com/content/tiny-killer-subs |title=Tiny Killer Subs – Can you get big bad bass from little bitty boxes? |last=Kumin |first=Daniel |date=June 2005 |publisher=Sound & Vision |access-date=2021-04-11}}</ref>