Tested/working speakers. Clean sound, both the master volume knob & bass volume knob turn smoothly and do not crackle as they turn.

Note: there does appear to be some sort of interference heard mostly when no audio is playing but the system is powered on. This could be from a variety of sources, and appears to be common with this 5.1 system. The interference is intermittent, and cannot be heard over music, but is sometimes audible when listening to quiet sounds or spoken word. **This information may not be mentioned with many other sold or currently available speaker Z506 sets**

The speaker cones and covers are all in great shape, as well as the exposed downward-facing subwoofer – see images.