Re: [Sursound] Infra sound Sub bass.
I think my use of the word significant was unwise but I would be interested to hear from anyone else who has looked in the lower spectrum below 30 Hz and found content. In measurements I made, just looking at a local orchestra, there was energy going down below 20hz The heating system was clearly registered at a steady 16hz but this noise was dynamic and matching that of the instruments. This was popular symphonic music, modern dance music as you surmised features much higher levels. Regards Jon On Friday, April 24, 2015, Elizabeth Durand Bill Houston bille...@cavtel.net wrote: I too doubt that most music has sub 20hz material except for some organ and percussion, electronic music and other recordings utilizing sub-harmonic synthesizers. Another obvious source of sub 20hz sound is unwanted environmental noise such as HVAC, traffic etc. Bill Houston Sent from my iPhone ___ Sursound mailing list Sursound@music.vt.edu javascript:; https://mail.music.vt.edu/mailman/listinfo/sursound - unsubscribe here, edit account or options, view archives and so on. -- next part -- An HTML attachment was scrubbed... URL: https://mail.music.vt.edu/mailman/private/sursound/attachments/20150424/92bd75e5/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.
Re: [Sursound] Infra sound Sub bass.
Considering most popular music these days is of the electronic variety or contains electronic processing. It all contains sub below 30, albeit rolled off down to 20. I don't know of a mix or record I have done that doesn't contain sub below 30. I manage it though to keep some headroom. Sympathetic resonances also occur during a record, which are.integral to the space, instrumentation, and position. It is generally unwise to put to much below 30 for radio as the whole mix will sound quieter compared to other mixes. Also if it's an old school dance master to vinyl, very low sub causes the needle to jump out of the groove. This is not to say the sub isn't hyped during playback as generally it is, to extremely low infa levels, and sometimes reinforced via floor shakers All the best Steve On 24 Apr 2015 09:10, Jonathan Burton jgb...@york.ac.uk wrote: I think my use of the word significant was unwise but I would be interested to hear from anyone else who has looked in the lower spectrum below 30 Hz and found content. In measurements I made, just looking at a local orchestra, there was energy going down below 20hz The heating system was clearly registered at a steady 16hz but this noise was dynamic and matching that of the instruments. This was popular symphonic music, modern dance music as you surmised features much higher levels. Regards Jon On Friday, April 24, 2015, Elizabeth Durand Bill Houston bille...@cavtel.net wrote: I too doubt that most music has sub 20hz material except for some organ and percussion, electronic music and other recordings utilizing sub-harmonic synthesizers. Another obvious source of sub 20hz sound is unwanted environmental noise such as HVAC, traffic etc. Bill Houston Sent from my iPhone ___ Sursound mailing list Sursound@music.vt.edu javascript:; https://mail.music.vt.edu/mailman/listinfo/sursound - unsubscribe here, edit account or options, view archives and so on. -- next part -- An HTML attachment was scrubbed... URL: https://mail.music.vt.edu/mailman/private/sursound/attachments/20150424/92bd75e5/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. -- next part -- An HTML attachment was scrubbed... URL: https://mail.music.vt.edu/mailman/private/sursound/attachments/20150424/a31df891/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.
Re: [Sursound] Infra sound Sub bass.
On 2015-04-22, Peter Lennox wrote: I'd be interested in any references indicating deleterious effects on hearing of high amplitudes at LF, if anyone comes across any No references from me, as usual, but there is a certain logic behind the claim. First, because of the loudness sensitivity curve, even very high levels of LF fail to register as being loud, eventhough the damage to acoustocilia correlates with overall amplitude and not frequency. So from that viewpoint the problem isn't that LF is more dangerous per se, it's that bass heavy mixes fool you into playing them too loud for too long. And second, I seem to remember that LF also doesn't as readily trigger our protective reflexes, like the stapedius one, which then compounds the error. -- Sampo Syreeni, aka decoy - de...@iki.fi, http://decoy.iki.fi/front +358-40-3255353, 025E D175 ABE5 027C 9494 EEB0 E090 8BA9 0509 85C2 ___ 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.
Re: [Sursound] ENVELOP - 3D Sound, on Kickstarter.com - SUB frequency range
On 2015-04-23, Stefan Schreiber wrote: How can this be if there are no fundamentals in this range? (See my list of piano keys/frequencies. Some instruments go down to about 30Hz. Organs can go even lower, but this is already one of the non-typical cases) That stuff is indeed there and mostly comes from percussion. The reason is that transients, being limited in time, don't break down into a discrete spectrum of harmonics, but into a continuous one which spreads out in inverse proportion to their temporal extent. (That's the uncertainty principle at work; it in fact has nothing to do with physics per se, but the properties of the Fourier transform and its time-frequency duality.) One way to see how that happens in practice is when you consider how a kick drum operates. When the mallet hits the membrane, it tries very hard to produce a step amplitude waveform, which of course has a spectrum reaching right downto DC. That then gets filtered by the broad modal structure of the drum itself, so that you get a broad band of energy mostly centered around the first mode of the instrument, plus some modulation of the parameters because the mallet pressing on the membrane initially tensions it more and heightens resonance structure in frequency. The result then couples in a frequency dependent manner to air, leading to extra low end rolloff because of the finite size of the instrument. To a first approximation you get something like a rapid downward chirp with a broad formant around the first mode, and energy arbitrarily low below that arbeit at progressively lower levels. On the Fourier side of things, sharply cutting off the LF content leads to low frequency ringing just as cutting HF content does on the other end. Because of the longer wavelength, though, in the time domain such manipulation reaches much farther away. So, paradoxically, a setup which (phase linearly/coherently) reproduces very low bass doesn't so much sound bassier, but causes LF transients to be better localised in time. That is, snappier and more kick than boom like. That's then why techno fiends like me favor setups without separate subs, closed designs instead of reflex ones, high damping and so on: the lower you can go and with the more gentle rolloff (which in a minimum phase system automatically leads to less phase dispersion), the better defined and the more energetic the beat. -- Sampo Syreeni, aka decoy - de...@iki.fi, http://decoy.iki.fi/front +358-40-3255353, 025E D175 ABE5 027C 9494 EEB0 E090 8BA9 0509 85C2 ___ 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.
Re: [Sursound] Infra sound Sub bass
The question isn't whether 'music' has frequencies below 1/zillion Hz. It's whether such content adds to the MUSIC. This is the case ONLY with organs reproduced properly. You can check this with DBLTs. The speaker that has come out top in every single DBLT it has been in nearly 2 decades (some dozen tests in all) was a small 6.5 ltr reflex with 70Hz cutoff. It was usually up against MUCH larger expensive speakers. No one has complained about its bass though some remark it's a bit down. As we did ABC (33% chance if guessing) rather than ABX (50% chance) tests, the probability that this result is chance is extremely small. There's also a lot of myth about how to design speakers for better defined more energetic beat. None of this comes out in DBLTs and this little ported box with terrible LF ringing always has comments like tuneful, well defined bla bla bass attributed to it. Going from 70Hz to 40Hz cutoff will more than triple the size and cost of the speaker .. and to go to 20Hz will more than double that again. You need to decide if you are getting any MUSICAL gains. The organ example ... differentiating 'pressure in the head' and 'velocity' (trouser flapping) sensations is an important part of the MUSIC. For percussion in modern music (??!), Bruce Willis destroying the universe other 21st century stuff, single subs are acceptable as they are all 'pressure in the head (and other parts of the anatomy)' sensations. Distributed subs fed with a mono signal allow this over a larger area. There's another myth that it's difficult to produce LF in small rooms. If all you want to do is dinosaur footsteps et al, this isn't the case. It's easier to pressurize a small room than a large one as you have to stuff less air in out. But a similar sensation is obtained by having someone beat you over parts of your anatomy with a blunt instrument. In a large venue this is cost effective because the required staff are already there. They are called bouncers. What IS difficult is to produce Velocity (trouser flapping) at LF. You have to MOVE all the air in the room. I have no comment on mixes with loadsa stuff below 30Hz that overload the majority of playback systems without any MUSICAL benefit ... whether its to cheat a A-weighted meter or not. ___ 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.
Re: [Sursound] Infra sound Sub bass
Amen, brother! Your argument is further supported by the evolution of the state of high-power silicon. Once upon a time a 200w/c amplifier was a mammoth. There are power amplifiers now that can deliver 90%+ of the power available from the line to the load. These sorts of amps made their debut in bandwidth limited applications like subs, but have migrated all the way to full-band applications in recent years. While I might be inclined to generalise in describing them as digital amplifiers, some are in fact, analog amps but with digital tracking power supplies. Quite recently I read about a multi-channel power amp for home theater applications that requires 2 x 15 A circuits. It delivers 7 channels capable of 300 w/c each. Things can be done with the express purpose of reproducing music, or for effect. Getting 40 Hz seems to be more about effect. Michael - Original Message - Subject: Re: [Sursound] Infra sound Sub bass From: Richard Lee rica...@justnet.com.au Date: 4/25/15 3:27 am To: 'Surround Sound discussion group' sursound@music.vt.edu The question isn't whether 'music' has frequencies below 1/zillion Hz. It's whether such content adds to the MUSIC. This is the case ONLY with organs reproduced properly. You can check this with DBLTs. The speaker that has come out top in every single DBLT it has been in nearly 2 decades (some dozen tests in all) was a small 6.5 ltr reflex with 70Hz cutoff. It was usually up against MUCH larger expensive speakers. No one has complained about its bass though some remark it's a bit down. As we did ABC (33% chance if guessing) rather than ABX (50% chance) tests, the probability that this result is chance is extremely small. There's also a lot of myth about how to design speakers for better defined more energetic beat. None of this comes out in DBLTs and this little ported box with terrible LF ringing always has comments like tuneful, well defined bla bla bass attributed to it. Going from 70Hz to 40Hz cutoff will more than triple the size and cost of the speaker .. and to go to 20Hz will more than double that again. You need to decide if you are getting any MUSICAL gains. The organ example ... differentiating 'pressure in the head' and 'velocity' (trouser flapping) sensations is an important part of the MUSIC. For percussion in modern music (??!), Bruce Willis destroying the universe other 21st century stuff, single subs are acceptable as they are all 'pressure in the head (and other parts of the anatomy)' sensations. Distributed subs fed with a mono signal allow this over a larger area. There's another myth that it's difficult to produce LF in small rooms. If all you want to do is dinosaur footsteps et al, this isn't the case. It's easier to pressurize a small room than a large one as you have to stuff less air in out. But a similar sensation is obtained by having someone beat you over parts of your anatomy with a blunt instrument. In a large venue this is cost effective because the required staff are already there. They are called bouncers. What IS difficult is to produce Velocity (trouser flapping) at LF. You have to MOVE all the air in the room. I have no comment on mixes with loadsa stuff below 30Hz that overload the majority of playback systems without any MUSICAL benefit ... whether its to cheat a A-weighted meter or not. ___ 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. -- next part -- An HTML attachment was scrubbed... URL: https://mail.music.vt.edu/mailman/private/sursound/attachments/20150424/5bb7b6d8/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.
Re: [Sursound] Infra sound Sub bass.
I too doubt that most music has sub 20hz material except for some organ and percussion, electronic music and other recordings utilizing sub-harmonic synthesizers. Another obvious source of sub 20hz sound is unwanted environmental noise such as HVAC, traffic etc. Bill Houston Sent from my iPhone ___ 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.
