I am using klank.dev to build a simple Karplus Strong string effect. It works ok up until around F above middle-C but can't get any higher. The example is pasted below, and you can try it here as well (klank only works on Firefox atm).
The line in question is del: Tuple (g'delay 0.00305) (SProxy :: SProxy "combine"). If you make the delay longer, ie 0.009, it gets lower as expected. But if you make it shorter, ie 0.002, at a certain point the pitch stops going up.
Does web audio have a hard lower limit for delays used in feedback loops? MDN reports that the minimum value is 0.0, which works when not used in feedback, but in a feedback loop I'm hitting this problem. Thanks for any insights!
module A.Felicidade.Pluck where import Prelude import Data.Symbol (SProxy(..)) import Data.Tuple (Tuple(..)) import Data.Typelevel.Num (D1) import FRP.Behavior (Behavior) import FRP.Behavior.Audio (AudioUnit, audioWorkletGenerator, g'add, g'delay, g'gain, graph, runInBrowser, speaker') import Foreign.Object as O import Record.Extra (SLProxy(..), SNil) import Type.Data.Graph (type (:/)) import Math(pi, sin, cos) import Type.Klank.Dev (Klank, Worklets, klank) worklets :: Worklets worklets _ res rej = ( do res [ "https://klank-share.s3.eu-west-1.amazonaws.com/K16029410960343210.js" ] ) scene :: Number -> Behavior (AudioUnit D1) scene time = pure $ speaker' ( graph { aggregators: { out: Tuple g'add (SLProxy :: SLProxy ("combine" :/ SNil)) , combine: Tuple g'add (SLProxy :: SLProxy ("gain" :/ "mic" :/ SNil)) , gain: Tuple (g'gain 0.9) (SLProxy :: SLProxy ("del" :/ SNil)) } , processors: { del: Tuple (g'delay 0.00305) (SProxy :: SProxy "combine") } , generators: { mic: audioWorkletGenerator "klank-lf-burst" (O.union (O.singleton "nsamples" 15.0) (O.singleton "freq" 1.0)) } } ) where rad = time * pi main :: Klank main = klank { run = runInBrowser scene , worklets = worklets } 
