Hearing distortion on soft synths (no effects used)

[Gates of H&I]

Recently I bought some new IEMs, and since then I've noticed I can often hear a sort of "cloudy" distortion on software synths that are set to use plain sinewaves, especially when they're playing pitches that are close together (not incredibly close, just within the same octave).

• There are no effects being applied to the signal
• I get this effect in a variety of DAWs and standalone synths
• It's audible both before and after rendering
• However, as far as I can tell, I only hear this in my own music

My question is: is this an actual fault I'm hearing in the audio, or are my IEMs broken? And if what I'm hearing is accurate, what's causing this?

Thanks

[UltraJv]

What sound card are you using? Are you set to 44.1? It may be aliasing or resampling. Maybe your IEMs are highlighting something that you never noticed before.

[lfm]

Synths and daws too often have a resampling algorithm - one for realtime audio and one for rendering. So a pitch is resampled to another depending on midikey to play.

So there might be a setting somewhere - which quality to use.

[Gates of H&I]

@ultrajv: I've heard the effect on things rendered on several computers. My current card is set to 44.1. kHz, but I've tried it at 96kHz and heard the same effect.

I'm actually starting to think this effect is just a build-up of the "beating" sound you get when playing two sine waves at close pitches. I considered that before, and I decided the sound wasn't much like that, but having tested it a little just now I'm not so sure.

[T-CM11]

Soundcard doesn't matter for rendering, it does for playback however.