[quote name='bassman7755' timestamp='1439790275' post='2845697'] I think some manufacturers quote a burst or "program" RMS (which is usually about 2x continuous RMS) and then quote peak as the peak-to-peak of that burst capability, thus their "peak" rating is around x4 their continuous RMS. [/quote]
The burst type rating used to be called (possibly still is) "music power" in hi-fi systems, and, as you say, was generally double the constant rating, and it was generally "peak music power" therefore four times the constant RMS rating.
There's some "measurement" called PMPO that can be found on some Ebay auctions for PC speakers. As 200W PMPO is apparently 4W RMS, that's quite a conversion factor.