Losing sound quality and FPS at lower GPU loads?

[Kevin11]

So I'm using a GTX 660 with an i7 6700k, I don't do a lot of gaming and I'm poor right now so it works for the time being, might grab a gpu on black video if there are any good deals on 960/970/1060/1070's but anyways I start dropping FPS at around 65% GPU load with 50fps and the sound quality starts to get worse when the FPS starts to drop, getting worse as the FPS gets lower. By 75% gpu load the sound quality is pretty bad and inaudible and the fps drops to 30. The GPU temperature never passes 64c and the gpu fan holds at about 34c even when the gpu load is at 80%. Any idea what's going on here? I could really use some help, mainly fixing the audio distortion. I am using an hdmi plugged into the GTX 660, I know for a fact it's not the display or the cord that's the problem because I've already done extensive troubleshooting, many hours of it at this point.

[Kantor]

is this a new problem or an ongoing one?

[GSTARR]

I assume you already checked drivers; after that I'm no help. Very peculiar

[Kevin11]

44 minutes ago, Kantor said:

is this a new problem or an ongoing one?

new since i switched to a new cpu and mobo, a better cpu and mobo

[Kevin11]

43 minutes ago, GSTARR said:

I assume you already checked drivers; after that I'm no help. Very peculiar

oh yeah, i've gone through ALL of the basic steps

[Kantor]

whats the capacity of your psu?

Edited September 18, 2016 by Kantor
spelling

[Kevin11]

8 hours ago, Kantor said:

whats the capacity of your psu?

750w, way more than i need

[Kevin11]

so after observing my gameplay on my other game, it appears to be the video engine load that's responsible not the gpu load, when the video engine load hits about 40% FPS starts to drop and the sound quality deteriorates, what could be the cause of this?