Subsonic ammo isn't available in Asylum. Suppressors on a 5.56 would be almost purely cosmetic. You still hear the snapping report of the bullet breaking the sound barrier and can determine the location from that assuming the shooter is farther than 300m away. Anything closer and you can still clearly hear the bang. I've played on Life servers that have suppressed 5.56. There's barely a difference on anything larger than 9mm. Give the cops 6.5 suppressors as an equalizer.