Volume control on Tidal

Probably something really easy but I can't seem to figure out how to control the volume when checking exclusive mode. I have tidal running on my MacBook pro to a Dacmagic 100 via usb. When nothing is checked I can control the volume through tidal, but when I check exclusive mode or force volume, the option to control volume is gone through tidal and doesn't control through mac either. The volume on the mac has 1 bar so should be very low, but when I push play it plays ridiculously loud. Before I keep experimenting and blow the speakers, does anyone know what I might be doing wrong. What controls the volume when exclusive mode is checked?