How to set Filter Frequency per voice?

dannytaurus

I'm trying to understand the polyphonic wizardry that goes on in HISE

I'm making a polyphonic synth. I need to add a HP filter, with a frequency of the played note. I'd like each voice (note of a chord) to have its own filter frequency, so the output of each voice has the correct filter frequency setting.

I have multiple Waveform Generators in a Synthesiser Group, with a Filter in the SG FX chain.

Does that achieve what I want? Or does that put all the voices through the same filter?

I'm setting the filter freq like this:

# init
const var HPF = Synth.getEffect("HPF");

function onNoteOn()
{
	const freq = Engine.getFrequencyForMidiNoteNumber(Message.getNoteNumber())
	HPF.setAttribute(HPF.Frequency, freq);
}

EDIT: reading through some more posts here, it looks like maybe I should be setting the filter freq with a Script Voice Start Modulator on the Filter Frequency Modulation instead? Would that make it polyphonic automatically?

Christoph Hart

The filter module is a bit special in this case because it renders monophonically until there is polyphonic modulation (either through an envelope or a voice start modulator) present in one of its modulation chains, then it switches to polyphonic rendering. This saves a lot of CPU in patches that don't require polyphonic filtering.

That means that you're example won't work because it still renders the filters monophonically. The quickest way to achieve that is to script a voice start modulator that calculates the modulation value for each voice based on its note number:

HiseSnippet 1083.3oc6X80aaTDDeuDukZCT0TUg.wCrOZiJAaml+oHDtIwtXQcpSboh2pVe2b1qx5cO1auzZg3c9XwGAj3K.eD3a.r6cW7cNwx1wk1RkvOXc6rybyucleyricWkzEBCkJjSomMN.PNeDt2Xgd3QCoLAp8wHm6f6PC0fhjH5vwAzvPvC43r9isBbJV.E+4u91CobpvExDgPOWxbgmvFwzYR6136YbdKpG7L1nbZ+vFsckhijbYjAOqiqhBntmSG.mPspsFF8czvgHmuDuyd8qt69964WGf98c2m5Uca.b2g1u+tUo0p64C64s8VagbtUSOlVp5ooZHz7ROT5Mt2P4KEIN34rPVeNXWTC0y34DwniFx3dcuL3DhPN3tYgp0SBU2G2g4wlHOKjc23MHYVjOn4r17fTsa.jbxAoBIPZCbOWEKPmsiEOeHtsvjA8olbSdnjnKx42vGIMJHzaNhdNzRYVLwfx6Ts5CHlupbfejvUyjBhTbhTCOUTtRoetTwR+RIxU2x2el6YciRx4fZlaaoCp4YXYQzn9f5AjKn7HXhhli+zwzasbwT2jScNEkh1Bl9oAP55VRtmMVYe95Y.TZXy7zOz9XplZSJoxL5E.JMyBGmigKLkAIonh3igvy0x.Sgv0xeFlizKhS0SSmrEZoaXhGSkCsIJQHSONeg3MfiUctbrkEhaf6xztCmMFWaFXzDodSfwzJyOF2z2Gb0Y.r.t0OtpkgKu6uch6+.7IRVHD636k7L4wf.T1fVs4zB82W1VnAKcKTm0m9bVX4JMllwkS+YzGpv6fVi+6PaeGVYMU26hWhwdrQAbno3BfaZejRfNF7oQb8kRml.0QJjACkBladNyYfVwFL.T4w9LOPORqMWxlI49MNC3.MLiT8murwSXBfpLwIXEqfu42jMy70mhSfKwx5IuN4sBKWdaA8+++tiqBM+d3tR93DRaKF2LnQLHJhSVLuFj0azRA+TDHbyhV+5ez3zLMHMllltYiSin7oht2swgr.Impdci7KfUWXIoGeBdxg5MEmt1L4zKLggSP8mmNUY7MQFuozSNEwGfuHceRrBjXMHSTo1hOIoChtVAGb9o9x7W4KrO1V3AuJdpOtzkxI9lvF4aHMECL8m1b.nmDGaIU16YryhdR7Hik6XNRleJgUqbRqT4fREUfNRIHkieceEod0JjulTa+82q5AWYLzT.ICtJdtYy4dCmlckYfuklOci3aQe+oc7mgSq+IV9x6O39N3S+O.XOSFoYhAcnlILdkoEgoRpmYZSWv.Tg.3FGgcVyR9RVW0t1BndfvKdwea9jtYM6ZmzMqc4luU7wHpqR9B2jRQaiuaGKwbtEw+cCEwcrqI0Pwkm4uhXjo0xKbcm9UcMCqupFt0pZ3CWUC2dUMbmU0vcWUC2awFZ67+nHsbTRcBB0oay3teNNMETCiOtjA8OvmtVih

Note that this sounds a bit out of tune and you have to fight against the weird modulation filter scaling that makes the default HISE filter so annoying to use.

Another option is to just use scriptnode, it's literally two nodes and one modulation connection:

HiseSnippet 1426.3oc6X0raaaDDdokWEamzfj1.zdqBHWRJBLjrSbbPOXYaIkJzHG0PGibycE4RqEhbWVxk1Von25gdquR9AHGBPdB5aP5SP6rKoDIsnskUbRPAJMfA24GNy2LyNyX2MPXQCCEAHik1cnOEYbCr4Ptr+18ILNpcCjwMwcHgRZPkXRaMzmDFRsQFFkdphfwhyizOueisHtDtEMkDBsmfYQeFyiISo1s9OxbcaQro6x7xH8Cq21Rv2V3Jh.+oDtJxmXMfb.cGhRr4vnefD1GY7c30VuW0G+Dm0cVgR60y5ID6pOhRsVizq2iqRpshsCcc6Gs5pHixMsYRQfojHogvGcKg8Py9hi3wFXOVHqmKUcnFxDrbLYz18Yt1cGEbBQHCb2zPUo3P0cvcX1rwzSCY2RynRpFYCZFycdtTsKgKYjwklO1ktM1zJf4KS4n7mqiaygLnCAxMYckXYQFmf2V.BvkK6QFPaE.GFqv8VqZ0GTA908+dmHtkjI3UD7cDR5y4269K8qKs3R+1RUNMKGmB4oLSfv0kFTHaU4Pv4o383Qd8nAOnxgD2H5XAA3mOlVd5hoVwnNifBdaNS9beZx4VBWaUrR89jY.TRXCd6ksaPjDURIgFHmOMPxTtiQC5gv0f3Tzh3FzvARgObQXh7GT4HribIx7kSpKZILf3QtbnJQwCYxgYuHdIpwpdt0XSqKdabWlzpew93bE3iPj5igOlby7KvMcbnVxTGbdbqWMqWCmdyuPr4uFdGAKjpM7WF+dkmR4z.UPq14zB8sSaKT+otEpQo73b9o6pQ9JtLxWPen4+LzZ7por8y3MqbcuWbjOZx77coM4GRcg1GIEPMnNjHW4Hp4Kf5H3B+9BNyJaMyKnx.1AGPCx56EBnMkRXHaJk6T+ETWJILSQUy5Oiwoj.HNQmwavW9IYElu9Fbr6VQU0W4CIuM+zk2tf9++e2wKUYdRL5l3tB2gwKe.1U4.eslTbcbkXNUZ8pZEtsx2hKZyfLKCfuhJKyLdeGp7HQv.MfRdG51G649i878C0t39NGWCsoqq3nsEd9rjTNf.MsTfpR9wRPgTAmSc2zSDA1y.aLGXzz5ksbEVCLYulpXoJOfEg2kvbUeAynPXcE6myMguidzgQo8nAgZadMb0kgefxoczWdK2hXAglgcIx9p5R0FPPQ.MXYqwECmEhxlKh2H+rjTYqQyfh8W.ldpHoZIdiRY1MJt.QcBJ+mSY9afaGtmhqEwEsmZOOEJ0eSk3i.hRzxXOXXBJGltoFSPEwxZdS5zIJ8A4ikw5dgId20wsBn+RDD7GlMosKI3.pLLYmPN0JtLPCf1fCs.1kXaCsn6RB.OC12VQM2GaLGU0XFfOV0bP+VXGlqR3kS3NI3Gq3kA9JVvToiGsgaqXqj9pJpvsoGq9T+C7zDVRGrhsVgDZ4vhQ4wm.D2gwShjo8+5PNNOs+3c0MkT+3KAoxYNfdTbPH2jtF4Cj6ROVtqP+AgTwg.vzFNiDcg+LSMzMi58z.Qju9PdWn9eVOYT7Dz2LRJ7f1M5F5nLfaoSAt5qt5613Tf6j27l6Nkf6t+8a0fqD9mNSP8RHU3.2osmBPoMcgfBhhmGNfmUNYhjDZkKYRprdArqDnneJFJHzE.kBp2.GbpfxO+UMdWR8lomPH6y3Gbkfm5+0q+8MJ.OZ5e7vSlTitG2+URM.syDJKhaxIvHe6qJz79Mt36LpFmaIDC7H58Fls+CAuPDIgBpNDXcdU60ch7Lgd1ViVXHbztBImqNpatIrRP0Q8dSXVSc1HgYswMl+TXCOhUfX+jIypA.Kno.Mx354RKh6nNWoF5vSm9USq22xJ+mZBEWYVUb0YUwGNqJ9nYUw0lUEe7rp35Wrhp+b9joep0afqqcaFO22XzkNX6Cz+Bw6v.BC

dannytaurus

@Christoph-Hart Super helpful, thanks!

How to set Filter Frequency per voice?

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