Research Which Supports Multiple Subwoofers

David Griesinger of Lexicon has written a research paper entitled ìSpeaker Placement, Enternalization, And Envelopment In Home Listening Rooms,î which argues for stereo subwoofers or better yet multiple subwoofers which challenges former work that has shown low frequencies not to be localizable. Griesingerís work is a study on producing bass outside the head (externalization) rather than inside and surrounding (envelopment), which are different properties than those previously studied before.Interestingly, in our reviews of numerous discrete soundtracts, whether encoded as DolbyÆ Digital or DTSÆ Digital Surround, we have praised deep bass localization and its effect on surround envelopment. Of course, our reference systems at Widescreen Review are specified with ìfull frequencyî loudspeaker delivery to at least 25Hz, plus a dedicated .1 low frequency effects enhancement subwoofer, preferbly two. While some of our reference systemsí main loudspeakers have 25Hz deep bass response, they are combined with a dedicated per channel subwoofer capable of below 25Hz response. We typically crossover the subwoofer to the main loudspeaker at 40Hz using outboard electronic crossovers.Griesingerís work is published in AES Preprint 4860 as presented in the Multichannel Sound session at the 1998 AES Convention. Tapes of AES papers and workshops are available from Mobile Tape at 805 295 0504.