Weird noise in headphones when bluetooth is on

so i have an external 4.1 bluetooth adapter (i use BrcmBluetoothInjector.kext) and when i turn on bluetooth and pair it with dualshock there is slightly audible noise. it stops when i turn it off or open bluetooth preferences pane and keep it in focus. i can still play music when it's noisy, it just gets mixed with it

audio: applealc, realtek 887, layout 1, gigabyte ga b85m d3v

cpu is i5-4440 (haswell)