Multiple sine waves sound distorted

[flappix]

Hi,
thanks for providing this library, it's pretty nice.

I'm just facing the problem that multiple sine wave generators are sounding very distorted when played together while playing them once at time sound good.

let s = [1,2,3].map ( x => { return new Pizzicato.Sound () } );
s[0].frequency = 440;
s[1].frequency = 554.37;
s[2].frequency = 659.26;

s.forEach ( (x) => { x.play() } );

This is an A major chord and should sound very harmonic but the sound I get is very disgusting.

Any help would be appreciated, thanks.