Spatial Impulse Response Rendering (SIRR) is a recent technique for reproduction of room acoustics with a multichannel loudspeaker system. SIRR analyzes the direction of arrival and diffuseness of measured room responses within frequency bands. Based the analysis data, a multichannel response suitable for reproduction with any chosen surround loudspeaker setup is synthesized. When loaded to a convolving reverberator, the synthesized responses create a very natural perception of space corresponding to the measured room. In this paper, the SIRR method is described and listening test results are reviewed. The sound intensity based analysis is refined, and improvements for the synthesis of diffuse timefrequency components are discussed.