4.1声音中的AKOscillator与4.0.4非常不同

Question

AKOscillator或AKAmplitudeEnvelope 4.1中有什么根本改变了吗？我的简单编钟声音的代码就像4.0中的魅力一样，但现在在4.1中是一种奇怪的异类。我不确定如何继续而不回到4.0。

以下是我设置和播放音符的代码：

var oscillators = [AKOscillator]()
var envelopes = [AKAmplitudeEnvelope]()
var mix: AKMixer?

let chime1Partials: [PartialAttributes] =
[
    PartialAttributes(partial: 0.5,  amp: 0.25, attack: 0.25,  decay: 0.35,  sustain: 0.0, release: 1.0),
    PartialAttributes(partial: 1.0,  amp: 0.75, attack: 0.025, decay: 0.135, sustain: 0.0, release: 1.0),
    PartialAttributes(partial: 2.69, amp: 0.35, attack: 0.025, decay: 0.25,  sustain: 0.0, release: 1.0),
    PartialAttributes(partial: 5.15, amp: 0.15, attack: 0.05,  decay: 0.25,  sustain: 0.0, release: 0.5)
]

class ChimeOscillator: NSObject, PlayerProtocol
{
    var fundamental: Double = 0.0
    var oscillators = [AKOscillator]()
    var envelopes = [AKAmplitudeEnvelope]()
    var mix: AKMixer?

    init(_ fundamental: Double, partials: [PartialAttributes])
    {
        oscillators.removeAll()
        envelopes.removeAll()

        self.fundamental = fundamental
        for attrib in partials
        {
            let osc = AKOscillator(waveform: AKTable(.sine))
            osc.frequency = fundamental * attrib.partial
            osc.amplitude = attrib.amp
            osc.start()
            oscillators.append(osc)

            let env = AKAmplitudeEnvelope(osc)
            env.attackDuration  = attrib.attack
            env.decayDuration   = attrib.decay
            env.sustainLevel    = attrib.sustain
            env.releaseDuration = attrib.release
            envelopes.append(env)
        }

        mix = AKMixer(envelopes)
        super.init()
    }

    func play(velocity: MIDIVelocity)
    {
        guard let mix = mix else{ return }
        let amp = Double(velocity) / 127.0

        //    Mixer Output Volume (Default 1.0)
        mix.volume = amp * amp

        _ = envelopes.map{$0.start()}
    }

    func stop()
    {
        _ = envelopes.map{$0.stop()}
    }
}