[Sursound] The birth of Ambisonics & the Soundfield Mike

2020-05-23 Thread Richard Lee
https://www.youtube.com/watch?v=X23hZNoSkUs The Calrec Soundfield mike, the practical implementation of Michael Gerzon & Peter Craven's invention, was how I got involved in microphone design. It was incredible just being with Michael .. a guy with a brain truly the size of a planet. The Mk4

[Sursound] practical HOA encoding

2019-06-11 Thread Richard Lee
.. a reply to stuff on the "Anyone had experience with AllRAD decoding to physical loudspeakers?" thread where Aaron brought up the topic of NFC. " A practical problem is that forward NFC filters have infinite gain at DC. Jerome Daniel's solution is to have a reference decoding distance for

Re: [Sursound] Hardest wearing outdoor speakers

2019-01-25 Thread Richard Lee
> Behringer ms10s that withstood months of tropical storms in the Amazon - so Have you got that model number right? I still think the cheapo solution is the way to go .. but it would be good to know what has worked for you .. even if it isn't 35 yrs. I get MS20 and loads of other stuff but

Re: [Sursound] Ambisonic Mic Comparison

2017-06-26 Thread Richard Lee
There's a number of issues brought up in this thread which Core Sound have been aware of for some time and have been attempting to address. But its difficult for a small company to make major changes on the small turnover. For what its worth, the 'new' PPAc will give around 1dB improvement in

Re: [Sursound] The BBC & Quadrophony in 1973

2017-01-07 Thread Richard Lee
If anyone has recordings of any of this Matrix H, HJ, UHJ stuff, please post a copy on http://ambisonia.com/ with a good description of what it is and the circumstances. I don't think UHJ is dead yet as the biggest present market for music is 2 channel stuff for headphones and UHJ gives

Re: [Sursound] External phantom battery source for TetraMic PPAc

2016-07-24 Thread Richard Lee
> Most days I would agree with you: but there is always Murphy's Law to contend with, and the specific case of this states that a PP3-powered recording device will fail only when a unique event is to be recorded. Ha! In my limited experience, Murphy is MUCH more likely to strike at

Re: [Sursound] Sursound Digest, Vol 96, Issue 3

2016-07-04 Thread Richard Lee
Can you give us more detail about these tests and perhaps put some of these natural recordings on ambisonia.com? The type of soundfield microphone used .. and particularly the accuracy of its calibration ... makes a HUGE difference to the 'naturalness' of a soundfield recording. Some good

Re: [Sursound] Using Ambisonic for a live streaming VR project

2016-06-13 Thread Richard Lee
> The main mechanisms for disambiguating 'cones of confusion' (and this includes front-back reversals) are: pinnae effects (Batteau) and head-movements (Wallach) - so, without either of these mechanisms at play, one would expect directional ambiguity. You can test the relative importance of

[Sursound] OT Stereo stage width - Was: Static stereo source in rotating soundfield, possible?

2016-04-01 Thread Richard Lee
Aaron Heller wrote > Marc Lavall, Eric Benjamin, and I put together a Trifield (three speaker > stereo) plugin and demo'ed it a Burning Amp last fall. It is hosted at https://bitbucket.org/ajheller/trifield/overview > There are also some plots that use Gerzon velocity and energy localization

Re: [Sursound] Soundfield MK IV Disassembly

2016-03-29 Thread Richard Lee
> I have a question for the keepers of ancient wisdom: how does one remove the capsule assembly from a Soundfield MK IV microphone? I have one on which the 1 kilohm "capsule heater" resistor has gone open circuit. The cone on the MK V and newer is split and comes apart pretty readily, but the

Re: [Sursound] Never do math in public, or my take on explaining B-format to binaural

2016-01-29 Thread Richard Lee
Just to bring everyone down to earth .. There are two easily reproduced experiments first carried out by prominent members of this group which put these effects into perspective. They are the Greene/Lee Neckbrace and Malham/Van Gogh Experiment The first shows 'real life' Fixed Head

Re: [Sursound] WFS in a small box?

2015-11-29 Thread Richard Lee
This is likely an implementation of Ambiodipole / Stereo Dipole / Transaural http://ambisonia.com/Members/ricardo/StereDpl.htm/ There's pretty pictures on the ISVR website that show 'some' measure of wavefield (soundfield?) synthesis takes place .. certainly more than with the usual +/-30

Re: [Sursound] Modified SoundField Mk IV

2015-10-19 Thread Richard Lee
ield Mk IV What's the difference between #641 and #650?? Dave On 19 October 2015 at 06:38, Richard Lee <rica...@justnet.com.au> wrote: > > Interesting: https://www.gearslutz.com/board/11410162-post650.html > > I endorse Rudy's mods described in #641 and #650 > > Ken

Re: [Sursound] Modified SoundField Mk IV

2015-10-18 Thread Richard Lee
> Interesting: https://www.gearslutz.com/board/11410162-post650.html I endorse Rudy's mods described in #641 and #650 Ken Farrar did something similar to his #641 mods in the Mk5 ... but I think his post should be titled "Where Beach Bums & Angels fear to Tread" :)

Re: [Sursound] SoundField rental in Spain

2015-06-26 Thread Richard Lee
A known floor noise of the dr-680 in high gain is from the phantom power, and the?Busman mod changes some components on the preamps, like some condensers and the opamps, and those condensers could be the solution on that kind of noise, but not all. The biggest noise on dr-680 mk1 is poor

Re: [Sursound] Directional confusion between different B-format players

2015-06-17 Thread Richard Lee
How is the Oktava Tetrahedral mike calibrated? In what form are the calibration files? Can you post a copy of the User Manual for it? http://www.oktavausa.com/ProductsPages/Ambient4DMic.html has no info at all. ___ Sursound mailing list

Re: [Sursound] Converting 16 mic array recording to B format

2015-05-19 Thread Richard Lee
Mathias, can you please post these recordings on ambisonia.com The Furse-Malham *.AMB format allows up to 3rd order These would be the first publically available live HOA recordings of music from a HOA mike and may re-surrect the discussion of HOA decoders Which Soundfield did you use? What

Re: [Sursound] Converting 16 mic array recording to B format

2015-05-17 Thread Richard Lee
Fons, have you heard any music recordings with EigenMike? No one seems to have tried. Elko has a standing invitation to bring EM to any venue that Aaron Eric are recording world class orchestras in good halls ... I mean obscure Mid West bands in non-descript halls :) They can reliably

Re: [Sursound] Converting 16 mic array recording to B format

2015-05-14 Thread Richard Lee
Duu.uuh!! http://parole.loria.fr/DEMAND/DEMAND.pdf states the microphones of the array ... are not calibrated with respect to each other, and so gain variations are to be expected: we found that the energy in some channels is consistently higher than in other channels. Algorithms working on

Re: [Sursound] Sursound Digest, Vol 82, Issue 2

2015-05-12 Thread Richard Lee
The strict answer to your question is in Gerzon's The Design of Precisely Coincident Microphone Arrays for Stereo and Surround Sound http://www.aes.org/e-lib/browse.cfm?elib=2466 There's a corrected copy at https://groups.yahoo.com/neo/groups/SoundfieldMic/files/Ricardo/. You might have to

Re: [Sursound] Infra sound Sub bass

2015-04-24 Thread Richard Lee
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

Re: [Sursound] ENVELOP - 3D Sound, on Kickstarter.com - SUB frequency range

2015-04-23 Thread Richard Lee
There is an important reason to maintain full Ambisonic capability to below 20Hz. It is a MUSICAL one. Go to a service at a large cathedral with good organ. At the end of the service, the organist will play something to show off while everyone is leaving. You can walk around and listen at

Re: [Sursound] Brendan Hearne

2013-11-26 Thread Richard Lee
I'm so sorry to hear that. In my younger days, I always thought of him as the handsome dashing young Prince of Ambisonia, a foil for Grand Vizier Malham. Ken Farrar was Chief of the Dwarves with Clem Beaumont his resident Sorceror. Michael was a Yoda type character with Geoffrey Barton sorta

Re: [Sursound] New Ambisonic VST Plugins

2013-11-25 Thread Richard Lee
It's certainly true that some decoding methods can become highly unstable when provided with an inadequate number of speakers and/or an uneven distribution. However, the Rapture3D decoders (including the TOA ones) do NOT have this problem. One of the core features of the Rapture3D decoder

[Sursound] Core Sound TetraMic

2013-11-04 Thread Richard Lee
Just a short note about noise. While the ST450 is slightly quieter than TetraMic, in practice, TetraMic noise has never been a problem when Recording Music .. even in very quiet studios. Paul Hodges recorded his son in the Warehouse, a well known studio in London, so you can judge for

Re: [Sursound] Eigenmike

2013-06-18 Thread Richard Lee
that's the main problem with the eigenmike: the higher the order, the narrower the bandwidth and the higher the lower boundary. which means that an eigenmike signal set will not usually be downwards-compatible - if you aim for a correct amplitude response for the full 4th order set, it will

Re: [Sursound] Eigenmike

2013-06-14 Thread Richard Lee
I must agree with Fons on Eigenmike. IMHO, Angelo's software for Eigenmike is loads better than what's supplied by the makers. Its nea...aarly good enough for recording music but certainly not there yet. There's a paper on the new software on Angelo's website. I'm not sure if there is a

Re: [Sursound] Patent application: Data structure for HOA

2012-10-30 Thread Richard Lee
Unless things have changed a lot, last I checked lossy compression messes up phase relationships, and that would be an issue for things like UHJ, which as long as portable stereo players with limited battery life (and thus limited CPUs), is the only viable, because stereo compatible,

Re: [Sursound] Patent application: Data structure for HOA

2012-10-27 Thread Richard Lee
As I've said ad nauseum, the guy who first integrates an Ambi decoder into VLC, getting around the evil Windoz mixer etc. gets to choose the data structure for next important Ambi format. This will be a lossy compressed format probably based on the public domain Vorbis. Ambisonia was the 1st

Re: [Sursound] Spherical speakers ?

2012-10-19 Thread Richard Lee
I mean that instead of a cone there is a sphere, and able to emit sound in all directions I'm guessing if it hasn't been done its because it presents considerable technical difficulties - still ... There are no serious difficulties as long as size $$ are not constraints. But apart from

[Sursound] CF spectrum vs L R in stereo etc

2012-10-15 Thread Richard Lee
.. was Somting for the Weekend - Commerisal 3D sound Sure, the center phantom image generated as a sum of two identical L/R signals sounds a little different. But little is the operative word. ... Most people do not notice this at all. It's not that we don't notice but that we are so used

Re: [Sursound] Somting for the Weekend - Commerisal 3D sound

2012-10-13 Thread Richard Lee
well, depends. iirc, theile's argument is that a two-speaker phantom source should be a mess in terms of spectrum, but isn't (as two-speaker stereophony demonstrates). so for some reason, the brain is able to sort it out. more than two correlated sources, and things go awry, e.g. L/C/R

Re: [Sursound] Question about plane waves, and the precedence effect

2012-09-28 Thread Richard Lee
except its not quite the same effect. If I hear a plan(ish) wave in nature such as in thunder or a very distant giant waterfall Distant thunder is often an extreme case of Proximity effect. Velocity components are boosted at LF compared omni components. You encounter this if you are using

Re: [Sursound] Super Stereo emulation (UHJ)

2012-07-25 Thread Richard Lee
No. Ambi Super Stereo isn't just feeding the stereo into a UHJ decoder. This is a post from 2006. I'd recommend a Width control so you can decide how wide you want your stereo. All the decodes here are basically the same with different Width settings. Only minor differences, with preference

Re: [Sursound] any idea's on the background of the stereo equations in

2012-07-21 Thread Richard Lee
You can't make naive predictions on what ambi stereo decode will sound like that; especially when you have j terms. You have to apply the full General Metatheory ... http://www.aes.org/e-lib/browse.cfm?elib=6827 It should be in Sampo's motherlode too. - Decode the W' X' Y' signals to a

Re: [Sursound] OT: Spatial music

2012-04-14 Thread Richard Lee
can a tetrahedral mic be used to create a room (correction) impulse response in B format? and how? Yes. I can make a sensible attempt today for an Ambi rig spaced away from the walls as the HiFi pundits and other gurus have mandated for years. This however has near zero Wife Acceptance

Re: [Sursound] question about simple equation

2012-03-16 Thread Richard Lee
cardioid = 1/2 ( sqrt2 W + X ) but for Mid-Side decoding from B-Format, where M is the same cardioid component, I often find this equation: M = sqrt2 W + X This is an instance of a patented Microsoft software invention called a Volume Control. There are also ancient hardware

Re: [Sursound] ST450 capsule assembly

2012-02-28 Thread Richard Lee
Svein Berge shows the ST350 capsule assembly at http://harpex.net/ My thanks to him. I want to know if this new stronger assembly, with the capsules secured by screw on rings, is used in the ST450 or if they have gone back to the old assembly using screws as in the Mk4, Mk5, ST250, SP422.

[Sursound] Gilbert Briggs Wharfedale

2011-12-28 Thread Richard Lee
http://www.impublications.com/content/a-pair-of-wharfedales I never met the Old Man but still cherish a letter in reply to a query of mine on how to enter the British loudspeaker industry. Like all who had even the slightest contact with him, his warmth, generosity and encouragement were never

Re: [Sursound] UHJ decoding and shelf filters

2011-12-15 Thread Richard Lee
http://ambisonic.info/info/ricardo/shelfs.html This is now only of historical interest. My latest thinking on Shelf Filters is encapsulated in BLaH3 Is my decoder Ambisonic? where Aaron's clarity puts me to shame and explains why I'm still a beach bum. The only useful info there which isn't

Re: [Sursound] UHJ decoding and shelf filters

2011-12-15 Thread Richard Lee
The actual shelf gains (the difference between LF and HF gain for any component) don't tell the real story. Changing the LF or HF gain for all components by the same amount doesn't modify the decoding, it just results in some EQ. Du...uh! I stand corrected. Shelf filters change the ratio

Re: [Sursound] SoundField: from Calrec to MBHO, what year?

2011-09-24 Thread Richard Lee
1989 was when Steve Jagger, Ken Farrar and some of the other original Calrec mob bought the company back from AMS. They left the Soundfield with AMS. AMS had problems making the mike consistently. When Soundfield Research took over, they dug Lynne out of retirement. She used to make the

Re: [Sursound] Questions regarding a very early 'Ambisonic' LP

2011-08-12 Thread Richard Lee
The change to UHJ at that time is very small and was made just to get rid of the need for another phase shifter in the decoder (IIRC). Any of the Classic Decoders, the Integrex, Minims, AD etc will decode this properly. I for one would be most interested in a copy of the recording as it

[Sursound] the recent 2-channel 3D sound formats and their viability for actual 360 degree sound

2011-07-24 Thread Richard Lee
There's loadsa good stuff being discussed here. If I can comment on just one or two When listening to this through a speaker rig, we hear this boost and tend to interpret it as meaning the sound is close especially in a dry acoustic with a Greene-Lee head brace etc., etc.,. However,

[Sursound] Book on Michael Gerzon, audio pioneer and music recordist

2011-05-28 Thread Richard Lee
Steve Thornton is selling a coffee table book based on his encyclopediac photographic record of OUTRS and other stuff. Be the first to brag a limited edition hardcover link which goes back to A. Blumlein Loadsa stuff on the rise fall of quad, surround and the early history of

[Sursound] HD Harwood: Stereophonic Image Sharpness, WW vol74 1968 p207-211

2011-05-28 Thread Richard Lee
Anyone got a copy of HD Harwood: Stereophonic Image Sharpness (Wireless World, vol 74, 1968, pp.207-211) ? ___ Sursound mailing list Sursound@music.vt.edu https://mail.music.vt.edu/mailman/listinfo/sursound

Re: [Sursound] Question regarding UHJ Encoding - Decoding

2011-05-05 Thread Richard Lee
This sqrt(2) factor is an endless source of confusion. It seems silly that W should be divided by sqrt(2) in recoding to restore its value, which was multiplied by this in the encode to UHJ. This sqrt(2) factor is WRONG. Where do people come up with such myths? The Encoding eqns on

[Sursound] Question regarding UHJ Encoding - Decoding

2011-04-30 Thread Richard Lee
I have questions about UHJ decoding too. Richard, how did you get your decoding eqns? My question is about http://en.wikipedia.org/wiki/Ambisonic_UHJ_format It has separate decoding eqns for 2 3 channel UHJ. They are consistent except for Y Y = 0.763*D + j*0.385*S

[Sursound] Mark Decker The Bells!

2011-04-30 Thread Richard Lee
IIRC, Mark Decker recorded a BBC radio drama where a man is killed by being tied up in a bellfry with the bells pealing away. Can't remember the title but I remember reading a web page where he describes this experience which was his first use of a Mk4 Calrec Soundfield. I'd appreciate a link

[Sursound] distance perception in virtual environments

2011-04-17 Thread Richard Lee
You must simulate at least 2 things. At close range, you must simulate the curvature of the soundfield. This is simply proximity for 1st order and the effect is, if anything, exaggerated. see the Appendix of Is My Decoder Ambisonic, Heller et al, AES San Francisco 1980 aka BLaH3 See Daniel

[Sursound] distance perception in virtual environments

2011-04-17 Thread Richard Lee
I hope you have a control where you measure real distance perception too. Not having a real control is a fault in many localisation experiments. ___ Sursound mailing list Sursound@music.vt.edu https://mail.music.vt.edu/mailman/listinfo/sursound

Re: [Sursound] horizontal-only decoder design for line sources

2011-03-23 Thread Richard Lee
[1] Loudspeakers and the Stereo Seat - G Millward, HFN, 1981? It's Millward, G; Loudspeakers and the Stereo Image, Hi-Fi News 29, nov84, according to http://decoy.iki.fi/dsound/ambisonic/motherlode/source/AmbiLoc2.pdf by a certain R.L and A.H. ;-) Thanks to Grand Vizier, Don Malham,

Re: [Sursound] horizontal-only decoder design for line sources

2011-03-22 Thread Richard Lee
I think this is a virgin field of research. On the practical design of line sources for large venues, it may be that we can only achieve ..more even coverage, as you increase the distance from a speaker system to the nearest listener. This also makes it rather more comfortable for the nearest

[Sursound] horizontal-only decoder design for line sources

2011-03-20 Thread Richard Lee
When I was RD tea-boy at Wharfedale, I spent time trailing around the country with Barry Fox our Promotions Manager, putting on lectures/demos shows. Part of the stuff we carted around was the Wharfedale Ambi rig which was - 12 x TSR110 speakers

Re: [Sursound] Death of Ambisonia.com

2011-03-09 Thread Richard Lee
I hope all of you will join BLaH in thanking Etienne for the immense efforts and huge amount of time money that resulted in Ambisonia. It must have seemed thankless at times. I am certain it has been a major factor in the resurgence of interest and much new work on Ambisonics and surround