"low frequencies" is correct and usable in written English.
It is a way of expressing that something does not happen or occur often. For example, "The company only received complaints at low frequencies."
At low frequencies, capacitive coupling becomes ineffective, however.
Most of the chemical absorption of sound occurs at relatively low frequencies, from about 1,000 to 5,000 hertz.
They tended to let low frequencies through and reflect the rest of the sound in unwanted directions.
Making a song sound as if it were coming from another room isn't hard: you lower the high frequencies, raise the low frequencies, and add some reverb.
"Interference is really a serious problem, especially at relatively low frequencies," Dr. Paul F. Goldsmith, director of the National Astronomy and Ionosphere Center, said via e-mail.
The earth is continuously vibrating, although at extremely low frequencies (on the order of once every couple of hundred seconds or so) and amplitudes.
At low frequencies, he said, the full array could map the entire sky in a day and night and do it again the next night.
His is truly soulful music, mixing the block-party sound of 90s New York with far-out jazz, hypnotic low frequencies and cocktail-shaking polyrhythms.
One consequence of this is that most names are found at low frequencies (Hannibal, Eustace, Phoenix).
At low frequencies of operation or under steady conditions, the second term is not important.
Fig. 7 Spectral slopes at low frequencies.
