HoaNFCtrl

Extension

Description

Higher Order Ambisonic signal (HOA) near-field effect (NFE) control transformer.

Class Methods

.ar

Examples

HOA with NFE decoding

Radial encoding followed by decoding with loudspeaker near-field compensation.// Inspect the ATK's speed of sound reference "Speed of sound: % m/s".format(AtkHoa.speedOfSound); // Inspect the ATK's reference radius "Reference radius: % m".format(AtkHoa.refRadius); // Inspect the ATK's channel/coefficient ordering "Coefficient ordering: %".format(AtkHoa.ordering); // Inspect the ATK's channel/coefficient ordering "Coefficient normalisation: %".format(AtkHoa.normalisation); // simple test... // boot rt server s.boot; // choose Ambisonic order ~order = 1 ~order = 2 ~order = 3 // choose an outbus, if need be ~outbus = 0 // encoding angles // azimuth & elevation ~theta = 0.0; ~phi = 0.0; // explicitly set encoding radius // i.e., radius != AtkHoa.refRadius ~encRadius = 2.0; // > AtkHoa.refRadius ~encRadius = 1.5; // = AtkHoa.refRadius ~encRadius = 1.0; // < AtkHoa.refRadius // decoding - panto decoder ~numChans = 8; ~orientation = \flat; ~beamShape = \basic; ~beamShape = \energy; // <-- good choice! ~beamShape = \controlled; ~match = \amp; ~match = \rms; ~match = \energy; // <-- good choice! ~decRadius = 2.0; // decoding / (actual) loudspeaker radius // open scope s.scope(~numChans, ~outbus); // audition ( { // saw params var freq = 110.0; var gain = -12; var sig; var hoa; sig = Saw.ar(freq, gain.dbamp); // encode with NFE hoa = HoaEncodeDirection.ar(sig, ~theta, ~phi, ~encRadius, ~order); // decode with NFE / loudspeaker near-field compensation HoaDecodeMatrix.ar( HoaNFCtrl.ar( // NFE control hoa, AtkHoa.refRadius, ~decRadius, ~order ), HoaMatrixDecoder.newPanto( // panto decoder ~numChans, ~orientation, ~beamShape, ~match, ~order ) ); }.play(outbus: ~outbus) ) // quit rt server s.quit

HOA with NFE encoding

Synthesise diffuse field at an encoding radius.// Inspect the ATK's speed of sound reference "Speed of sound: % m/s".format(AtkHoa.speedOfSound); // Inspect the ATK's reference radius "Reference radius: % m".format(AtkHoa.refRadius); // Inspect the ATK's channel/coefficient ordering "Coefficient ordering: %".format(AtkHoa.ordering); // Inspect the ATK's channel/coefficient ordering "Coefficient normalisation: %".format(AtkHoa.normalisation); // simple test... // boot rt server s.boot; // choose Ambisonic order ~order = 1 ~order = 2 ~order = 3 // choose an outbus, if need be ~outbus = 0 // open scope s.scope(~order.asHoaOrder.size, ~outbus); // explicitly set encoding radius // i.e., radius != AtkHoa.refRadius ~encRadius = 10.0; // >> AtkHoa.refRadius ~encRadius = 5.0; // > AtkHoa.refRadius ~encRadius = 2.0; // > AtkHoa.refRadius ~encRadius = 1.5; // = AtkHoa.refRadius ~encRadius = 1.0; // < AtkHoa.refRadius // audition ( { // params var gain = -12; var hoa; // diffuse field (synthesized at AtkHoa.refRadius) hoa = ~order.asHoaOrder.size.collect({ BrownNoise.ar(gain.dbamp) }); // encode with NFE HoaNFCtrl.ar( // NFE control hoa, ~encRadius, AtkHoa.refRadius, ~order ); }.play(outbus: ~outbus) ) // quit rt server s.quit

HOA with NFE imaging

Translate from source radius to target radius.// Inspect the ATK's speed of sound reference "Speed of sound: % m/s".format(AtkHoa.speedOfSound); // Inspect the ATK's reference radius "Reference radius: % m".format(AtkHoa.refRadius); // Inspect the ATK's channel/coefficient ordering "Coefficient ordering: %".format(AtkHoa.ordering); // Inspect the ATK's channel/coefficient ordering "Coefficient normalisation: %".format(AtkHoa.normalisation); // simple test... // boot rt server s.boot; // choose Ambisonic order ~order = 1 ~order = 2 ~order = 3 // choose an outbus, if need be ~outbus = 0 // open scope s.scope(~order.asHoaOrder.size, ~outbus); // encoding angles // azimuth & elevation ~theta = 0.0; ~phi = 0.0; // explicitly set (source) encoding radius // i.e., radius != AtkHoa.refRadius ~encRadius = 2.0; // > AtkHoa.refRadius ~encRadius = 1.5; // = AtkHoa.refRadius ~encRadius = 1.0; // < AtkHoa.refRadius // target (translation) radius ~reEncRadius = 3.0; // re-encoding radius > AtkHoa.refRadius ~reEncRadius = 1.5; // re-encoding radius = AtkHoa.refRadius ~reEncRadius = 1.0; // re-encoding radius < AtkHoa.refRadius // audition ( { // saw params var freq = 110.0; var gain = -12; var sig; var hoa; sig = Saw.ar(freq, gain.dbamp); // encode with NFE hoa = HoaEncodeDirection.ar(sig, ~theta, ~phi, ~encRadius, ~order); // re-encode NFE HoaNFCtrl.ar( hoa, ~reEncRadius, ~encRadius, ~order ); }.play(outbus: ~outbus) ) // quit rt server s.quit

Radial modulation

The use of two HoaNFCtrl transformers offers the possibility of modulation at a given radius.// Inspect the ATK's speed of sound reference "Speed of sound: % m/s".format(AtkHoa.speedOfSound); // Inspect the ATK's reference radius "Reference radius: % m".format(AtkHoa.refRadius); // Inspect the ATK's channel/coefficient ordering "Coefficient ordering: %".format(AtkHoa.ordering); // Inspect the ATK's channel/coefficient ordering "Coefficient normalisation: %".format(AtkHoa.normalisation); // simple test... // boot rt server s.boot; // choose Ambisonic order ~order = 1 ~order = 2 ~order = 3 // choose an outbus, if need be ~outbus = 0 // encoding angles // azimuth & elevation ~theta = 0.0; ~phi = 0.0; // explicitly set encoding radius // i.e., radius != AtkHoa.refRadius ~encRadius = 2.0; // > AtkHoa.refRadius ~encRadius = 1.5; // = AtkHoa.refRadius ~encRadius = 1.0; // < AtkHoa.refRadius // decoding / re-encoding - spherical design (A/B-format) ~numChans = 24; ~beamShape = \basic; ~beamShape = \energy; ~beamShape = \controlled; ~sphDesign = TDesign.newHoa(~numChans, order: ~order); // modulation ~modRate = 20.0; ~modRate = 10.0; ~modRate = 5.0; // open scope s.scope(~order.asHoaOrder.size, ~outbus); // audition ( { // saw params var freq = 110.0; var gain = -12; var sig; var hoa; var aformat; sig = Saw.ar(freq, gain.dbamp); // encode with NFE hoa = HoaEncodeDirection.ar(sig, ~theta, ~phi, ~encRadius, ~order); // decode with NFE aformat = HoaDecodeMatrix.ar( HoaNFCtrl.ar( // NFE control - decode at encoding radius, the "look" radius hoa, AtkHoa.refRadius, ~encRadius, ~order ), HoaMatrixDecoder.newSphericalDesign( // a-format decoder ~sphDesign, ~beamShape, ~order ) ); // modulate amplitude of "virtual loudspeakers" - in a-format aformat = aformat * ~numChans.collect({ LFNoise2.ar(~modRate).range }); // aformat = aformat * ~numChans.collect({ LFNoise2.ar(~modRate) }); // re-encode with NFE HoaNFCtrl.ar( // NFE control - re-encode at encoding radius, the "look" radius HoaEncodeMatrix.ar( aformat, HoaMatrixEncoder.newSphericalDesign( // a-format encoder ~sphDesign, ~beamShape, ~order ) ), ~encRadius, AtkHoa.refRadius, ~order ); }.play(outbus: ~outbus) ) // quit rt server s.quit