Centralized systems incorporate a central control point for the masking generator, equalizers and amplifiers. All speaker zones are wired back to the "rack" or central location. This allows for volume controls and sound masking, paging and music to be controlled and maintained in a single location. This approach also allows for upgrades as new technology arrives.

In a distributed system there is no central "rack" location. Every individual speaker is its own self contained masking system. While this basic approach is acceptable in very small projects with little or no growth potential it has disadvantages for medium to large size projects. Distributed systems cannot be easily re-tuned or maintained on larger projects.

Also, distributed systems lack 1/3 octave band equalization tuning capability and as such do not meet ASTM standards for professional sound masking systems.