A method and system for keeping endpoints such as speakers and displays synchronized via feedback based on the actual output of the endpoints. A source of audiovisual content transmits corresponding digital data to one or more endpoints, such as over a home network, where it may be buffered and/or decoded for playback. Microphones or the like sense actual (post-buffering/decoding) output from one or more endpoints and feed it back to a synchronization mechanism. The synchronization mechanism employs pattern matching or similar techniques to determine whether and how to adjust the timing of endpoints to synchronize their actual outputs. Synchronization may be accomplished by controllably delaying transmission and/or other processing, by controllably changing the rate of advancing in a buffer, and/or by jumping ahead in a buffer. The synchronization mechanism may adjust multiple endpoints, e.g., when limited buffer size limits the amount of adjustment a single device can provide.