"deep notes" is a correct and usable phrase in written English.
You can use it to describe a sound that has particularly low, resonant tones. For example, "The cello player played deep notes that echoed throughout the entire hall."
His low, deep notes are strong but a bit gravelly.
Anthar also used his voice, singing long, deep notes.
Correspondingly, any deep notes produced by the jets must be much weaker than needed to prevent cooling and star formation.
Dr. Jenny Cho, one of several physicians who are on hand during Metropolitan Opera performances, said opera's deep notes required core strength and a good cardiovascular system.
He heard harsh mouthfuls of words with deep notes — it was not a mellifluous language like the bright bubbling of water over rocks of his language.
Eventually powerful jets should be produced by the black hole in repeated outbursts, forming the deep notes seen in objects like Perseus and stopping the starburst.
Polmo Polpo, a band headed by the guitarist and sound artist Sandro Perri, unfolded richly arpeggiated improvisations over deep bass notes.
A single sound — a deep bass note or a detuned kick drum, or maybe both — serves as the rhythmic anchor.
Wagner's "Ring" begins with a demonstration: from one deep note, wave upon wave of majestic harmony flows.
Dr. Dre, also a Schifrin licensor, had less luck using George Lucas's deeply proprietary "THX Deep Note" for the opening of his "2001" album.
35 Dre v George Lucas According to Lucasfilm, Dre's opening sound effect on 2001, copied its trademarked Deep Note "audible logo" for THX cinema sound systems.
