OK Dave - I was mostly referencing to "high quality Subs" in home/small to medium sized listening spaces..
I do not really have experience in large scale sound systems - here is a few google finds. The chest cavity resonates between 80 to 95 hz was my thinking and seems to be correct, read Entry #25 in link below ... - but as usual in a discussion forum not all agrees. http://www.diyaudio.com/forums/subwoofers/195046-chest-thump-trousers-flappin.html But as usual in this discussions there are some ideas that do not make sense with the laws of physics - for example the directionality of low frequency sounds. Entry #35 The 'punch' of percussive sounds are roughly concentrated between 100-800Hz. The sounds above 800Hz are considered as part of the ‘attack’ of the sound. The 'attack' of the sound gives an accent to the ear of the 'punching' sound. Although the 'attack' can not be felt by the body, it does make the ear correspond to the part of the audio band that can be felt. This gives more evocative feel to the punch. For instance, if you eq individual instruments like a drumkick with more >1500Hz to raise the attack, it will also sound like it adds more 'punch'. (Of course the point where the feeling is taken over by hearing is not centred on one spot like 800Hz, but instead covers a wider area.) Entry #43 i can feel it well in my chest at ~85db using my reference system. (+- 2db 16Hz-22kHz) below 85 it's still there just not really tactile. This is really interesting where the audio review descriptions are defined by frequency http://www.independentrecording.net/irn/resources/freqchart/main_display.htm Factors Influencing the Perception of Bass https://acoustics.org/pressroom/httpdocs/133rd/4aaa6.html Although the direction of arrival did have a small effect, changes in level had a much stronger influence and these results confirm that added low frequency reflections could be used to increase the perceived strength of bass sounds. Conclusions The perceived strength of bass sounds is not influenced by low frequency reverberation time. The levels of both the early- and late-arriving bass sounds influence the perceived strength of bass sounds. Subjects' evaluations of bass sounds are more sensitive to late arriving low frequency sounds than to early arriving low frequency sounds. Added low frequency reflections can be used to compensate for the seat dip effect and increase the perceived bass strength in concert halls. --- Maybe the relevance disappeared :-). I still belive directionality of low frequency sounds are defined by the overtones. But as one of my old teachers said: Believe you can do in church, an engineer you have to know. Best Regards Bo-Erik -----Original Message----- From: Sursound [mailto:sursound-boun...@music.vt.edu] On Behalf Of Dave Malham Sent: den 21 april 2015 18:22 To: Surround Sound discussion group Subject: Re: [Sursound] ENVELOP - 3D Sound, on Kickstarter.com - SUB frequency range Hmmm...I have to say that I am simply not convinced (and haven't been for many years) that the figure 80 Hz is appropriate except in domestic sized rooms where the wavefronts are too befuddled by the early arrival of reflections, usually well within a wavelength. I have been able to localise subs far too often at much lower frequencies in concert halls to accept it without the qualification. Even if our hearing - which at these frequencies is not just via the ears, but also through, for instance, chest cavity resonances - cannot directly perceive the direction of low frequency sounds, even the best subs distort producing higher frequency components and there is always the possibility (read near certainty in any real rig) that something will rattle which definitely will be localisable. Dave :-) On 21 April 2015 at 11:39, Bo-Erik Sandholm <bo-erik.sandh...@ericsson.com> wrote: > Why not follow the well known and also psychoacoustic based corner > frequency of 80 Hz with 24/18db octave filters. > > If the subwoofers are of good quality and do not produce distortion > products that are in higher frequency ranges, clean sounds below > 80Hz are not possible to localize without higher frequency being part > of the played sound. > > The improvement of having several Subwoofers in a room to even out > room responses and resonances, and lowering the individual sub woofers > higher frequency distortion products by playing the individual sub's > at a lower level may be the main reason you like more subwoofers.. > As a comment - many subwoofers are self powered or ofte driven by > external power amplifiers and not only by a 5.1 or 7.1 home theater amplifier. > > We should not try to solve low frequency replay problems by thinking > they are ambisonic related when they are not :-) > > The sound pressure derivate or wave front difference from 2 close ( > 1-4 > meters) for a pair of subs (or 3 or 4 ) are not detectable - and where > can you get a stereo/ambisonic signal that contains those timer differences? > > I am building my rig using KEF Eggs from KHT-2005 setups. > > Bo-Erik Sandholm > > > -----Original Message----- > From: Sursound [mailto:sursound-boun...@music.vt.edu] On Behalf Of > Stefan Schreiber > Sent: den 20 april 2015 00:54 > To: Surround Sound discussion group > Subject: Re: [Sursound] ENVELOP - 3D Sound, on Kickstarter.com > > Steven Boardman wrote: > > >If there is an LFE sub in a playback system, that also has full range > satellites,. Why not use it? Music playback on these systems can still > use the full range, but also use the sub for dynamic effect. > Particularly when it is dialled low. It allows the program material > to be louder, as one is using all the available headroom. It also > doesn't register so much on Dolby meters when cinema broadcast is > required. Which also means the volume can be pushed even more. > >As long as it's used sparing for the very lows, then it won't mess > >managed systems either… > > > >Best regards > > > > > >Steve > > > > > > Or maybe we should use good "full-range" speakers down to about 40 - > 50 hz, and still use a sub for the lowest octave or so? (Because if > there is musical content 50 hz, the reproduction system should adopt > to the music; the opposite way doesn't convince me so much... ) > > Best, > > Stefan > > >On 19 Apr 2015, at 22:17, Stefan Schreiber wrote: > > > > > > > >>Jörn Nettingsmeier wrote: > >> > >> > >> > >>>On 04/19/2015 07:29 PM, Stefan Schreiber wrote: > >>> > >>> > >>> > >>>>Otherwise we don't need any sub, and Jörn and Marc could save some > >>>>money... :-) > >>>> > >>>> > >>>the saving money part happens when you stop pushing every single > loudspeaker down to 20 hz (because extended lf capability equals size > and weight and money, and as we all know, there are many many > loudspeakers in higher-order ambisonics). > >>>it's just not very economical. > >>> > >>> > >>I am not pushing anything. I just gave some "empirical feedback" > >>that > the lowest piano key is 27.5 hz and for example the lowest double bass > note > 32.7 hz (C extension) or even lower. If you want to reproduce the > fundamentals and not just overtones, you probably need a subwoofer. > >> > >> > >> > >>>and i'd like to stress that subwoofer != lfe. > >>> > >>> > >>Did I pretend anything different?! There is obviously no LFE channel > >>in Ambisonics, but in the cited cinema formats you had. (10.2, 22.2) > >> > >>And I was also referring to some former 5.1 discussion. (LFE needed > >>for music mixes, or not.) > >> > >>In this sense, we have a mixed discussion. (You still could argue > >>that LFE is not needed in a 5.1 mix; in practice, there could be > >>some issues without LFE. Depends maybe on the intelligence of your > >>equipment...) > >> > >> > >> > >>>i don't need an lfe for music, even less so with all the +/- 10dB > >>>guesswork :-D but i do like my 10 octaves (or the 9.5 which i can > >>>still > hear). > >>> > >>> > >>You will experience still your 10 listening octaves if you turn up > >>your > hf amplification a LOT and fry your speakers... :-D > >> > >>Best, > >> > >>Stefan > >> > >>_______________________________________________ > >>Sursound mailing list > >>Sursound@music.vt.edu > >>https://mail.music.vt.edu/mailman/listinfo/sursound - unsubscribe > >>here, > edit account or options, view archives and so on. > >> > >> > > > >_______________________________________________ > >Sursound mailing list > >Sursound@music.vt.edu > >https://mail.music.vt.edu/mailman/listinfo/sursound - unsubscribe > >here, > edit account or options, view archives and so on. > > > > > > > > _______________________________________________ > Sursound mailing list > Sursound@music.vt.edu > https://mail.music.vt.edu/mailman/listinfo/sursound - unsubscribe > here, edit account or options, view archives and so on. > _______________________________________________ > Sursound mailing list > Sursound@music.vt.edu > https://mail.music.vt.edu/mailman/listinfo/sursound - unsubscribe > here, edit account or options, view archives and so on. > -- As of 1st October 2012, I have retired from the University. These are my own views and may or may not be shared by the University Dave Malham Honorary Fellow, Department of Music The University of York York YO10 5DD UK 'Ambisonics - Component Imaging for Audio' -------------- next part -------------- An HTML attachment was scrubbed... URL: <https://mail.music.vt.edu/mailman/private/sursound/attachments/20150421/080e9689/attachment.html> _______________________________________________ Sursound mailing list Sursound@music.vt.edu https://mail.music.vt.edu/mailman/listinfo/sursound - unsubscribe here, edit account or options, view archives and so on. _______________________________________________ Sursound mailing list Sursound@music.vt.edu https://mail.music.vt.edu/mailman/listinfo/sursound - unsubscribe here, edit account or options, view archives and so on.
