Mac audio output bypasses the user's volume setting

Some people who have downloaded my DSP Filters application have reported that it bypasses the system volume setting. Not sure what’s going on. Here’s the app installer:

DSP Filters Installer for Mac

Really? I’ve no idea how you’d make it do that, even if you wanted to! Certainly the juce coreaudio classes just works in the normal way (I had a quick test of the demo just to make sure though). Do they perhaps have multiple output cards, only one of which is controlled by the system volume?

It works for me, when I try the Dsp Filters demo that I uploaded, which uses the latest tip. I had to disable the sound settings dialog calls from my app because they broke the iOS build. So maybe they have multiple cards. I will investigate.