The idea that one can manipulate standing waves with multiple subs is pretty well studied. It's separate from the idea of localizing low frequencies but does imply the usefulness of have multiple subs to improve frequency response and avoid bass peaks and nulls at locations throughout a space. Harmon ( the JBL division), who would like to sell a lot of subwoofers, has studied this - here's a reference article (AES 2006): http://www.wghwoodworking.com/audio/low-frequency_optimization_using_multiple_subwoofers.pdf
<http://www.wghwoodworking.com/audio/low-frequency_optimization_using_multiple_subwoofers.pdf>a quick google search will yield a good handful of derivative articles - like this one: http://www.bgradia.com/PDFs/Better%20bass%20through%20multiple%20subwoofers.pdf <http://www.bgradia.com/PDFs/Better%20bass%20through%20multiple%20subwoofers.pdf> best, jim 2011/6/5 Marc Lavallée <m...@hacklava.net> > Le Fri, 03 Jun 2011 10:47:23 +0100, > dw <surso...@dwareing.plus.com> a écrit : > > > > I did a basic experiment with twos subs and a sound generation > > > software (PureData with the equal_power_pan extension). I panned a > > > bass sine tone from left to right and back, changing the frequency > > > between 40Hz and 160Hz. I was able to localize the sine tone at > > > certain frequencies, depending on my position in the room; at 70Hz > > > the tone was very easy to localize. So it's definitely possible to > > > create a sound field with directional bass, intentionally or not. > > > > I suspect you are just modulating the standing wave pattern.. > > Yes, I was probably just doing that. > Room modes, standing waves, etc. But... > > The consumer audio industry stated with authority that bass should just > fill the room, and that that's what sounds good. I was not supposed to > buy a second sub, I was supposed to stick one in some corner and be > happy forever. > > One paper caught my attention: "Spatial auditory display using multiple > sub-woofers in two different reverberant reproduction > environments" (easy to google). It studies our ability to localize a > pair of left/right subs and front/back subs, in an anechoic room and a > small domestic room, for frequencies ranging from 40 to 100Hz. In > both rooms, our ability to localize front or back bass tones is very > bad (about 40% accuracy). In a anechoic room we can localize the > left/right bass tone without error. In a domestic room the results are > not as good, but we are still able to localize L/R bass tones down to > 80Hz with 80% accuracy. I suppose that the same test in a small room > with bass traps would give better results. > > I once asked Fons A. what kind of speakers I should get for Ambisonics > and he replied that full range speakers are mandatory. With my small > room and small budget it was a challenge. It took me a while to figure > how to build lots of bass reflex enclosures for small full-range > drivers, and I was ready to build them. Then I learned that a dedicated > decoder can be used with three subs. Someone mentioned the KEF "Eggs" as > good domestic speakers, and I was lucky to find three sets of > discontinued KEF home theatre speakers at a very good price (with the > smallest "Eggs" and the "Kube-1" sub). The Eggs are excellent. The Kube > doesn't have much bass extension, but it works. So now I am playing > with my new toys, but I'm not ready to install an ambisonics setup (I > need to find a sound card with 16 outputs). > > In the meanwhile I am adapting my XTC setup in order to use two > satellites and two subs. I must admit that your filter is my favourite > right now, although I should compare it with the others (RACE, BACCH) > later this summer. > > > Here is the 'uncut' version, if you would like to compare. I think it > > is less suitable for general use, so don't want it to be the offical > > distributed version. You seem to be the only one interested. The file > > will be removed in a day. > > There's a bit more bass coming out of your "uncut" filter, but > there's some cancellation when the bass signal is mono (equal in both > channels). I still prefer when the stereo signal is sent directly to a > pair of subs at +-30 degrees. > > -- > Marc > > _______________________________________________ > Sursound mailing list > Sursound@music.vt.edu > https://mail.music.vt.edu/mailman/listinfo/sursound > -- Jim Moses Technical Director/Lecturer Brown University Music Department and M.E.M.E. (Multimedia and Electronic Music Experiments) http://jimmoses.wordpress.com/ -- Jim Moses Technical Director/Lecturer Brown University Music Department and M.E.M.E. (Multimedia and Electronic Music Experiments) -------------- next part -------------- An HTML attachment was scrubbed... URL: <https://mail.music.vt.edu/mailman/private/sursound/attachments/20110606/0777bce0/attachment.html> _______________________________________________ Sursound mailing list Sursound@music.vt.edu https://mail.music.vt.edu/mailman/listinfo/sursound
