Surf LFO

A signal whose frequency is generally below the human ear's ability to hear as a tone, usually 20 cycles per second [Hz]. This plugin will generate mono or stereo surf which sweeps between a lower and upper filter frequency. Stereo surf also sweeps back-and-forth somewhere between the left and right audio channels. To generate stereo surf, first open a new stereo track in Audacity. Do this by ALT, P, S in Audacity pre-1.3, or ALT, T, N, S in 1.3 and later.

Parameters:

1. Mono or stereo surf: [1=mono 2=stereo] Mono surf is heard only in the center between the two speakers, or in the middle of your head when wearing headphones. Stereo surf sweeps back-and-forth somewhere between the two audio channels, depending on the next setting, Stereo Spread. 2. Stereo spread: [stereo only: percent] The larger this value, the more widely the stereo surf will move back-and-forth between the left and right audio channels. When this value is above zero, the deeper section of the surf sweep will be heard more in the left channel; below zero, the deeper section of the surf sweep will be heard more in the right channel. 3. Fade-in and fade-out times: [seconds] To smoothly fade in and fade out the volume at the start and end of the surf. 4. Surf duration: [minutes] (up to 60) 5. Surf type: [0=white noise 1=pink noise] White noise is more of a "hissing" sound, whereas pink noise is a lower "rushing" sound. Technically, white noise is "equal energy per frequency", whereas pink noise is "equal energy per octave" 6. Surf sweep frequency: [Hz] Sets how slow or fast the surf sweeps between the lower and upper filter frequencies, and the left and right channels [for stereo surf]. 7. Lower filter frequency: [Hz] 8. Upper filter frequency: [Hz] Both the above determine how low and how high the lowpass filter sweeps the surf noise. 9. Bass frequency to boost: [Hz] You can boost the volume of frequencies of the surf sound below this setting, to get a deeper-sounding surf. Somewhat equivalent to the bass knob on your stereo. 10. Bass boost : [dB] Sets how much to boost the above bass frequency. 0 dB means no boost, 6 dB means double the amplitude of the bass frequency, and so on.

Note: If you get an error message "Nyquist returned too many audio channels", this means you tried to generate stereo surf without first having opened a blank stereo track in Audacity. See instructions at the start of this help file for instructions on how to do this.