Should be but you need to go to System Preferences > Sound to make sure your speakers are selected.
Screenshot of Output tab in Sound preferences, with list of sound options. My USB speakers are selected.
Screenshot of the Sound Effects tab in Sound Preferences, again with my USB speakers selected, clicking on one of the sound files in the list plays the sound, easiest way to test if your speakers are working.
They should also be showing up in System Information > Audio, see screenshot below showing my Audio options. Go to About This Mac, Select 'System Report' and navigate down to the Audio report.
System Information > Audio Report from my iMac1 system