Re: [LAU] placement.

Jorn, i'm not that far into it yet, and have no coding experience or
mathematical degree to back me up. :) Just a former orchestral musician and
composer trying to make his way, who has to use his ears, and a slide rule,
to work things out.

As soon as i know what 2nd level ambisonics are, i'll have a better idea
though. :)

Anyway, back to the books........

Alex.

On Tue, Jan 13, 2009 at 6:28 PM, Jörn Nettingsmeier <
nettings@email-addr-hidden-hochschule.de> wrote:

> alex stone wrote:
> > Jorn, thanks for feedback. I've just tried one of Fon's amb plugs, and
> > it repeatedly crashed ardour, so i think i'd better fix that before
> > going further.
>
> interesting. i've never had problems with those plugins in ardour. which
> specifically? and which ardour version?
>
> > As for mike bleed, it's not a full multimix of pseudo mic blend, but
> > more a 'hint' of signal from adjacent instruments. It's artifical, imho,
> > to completely remove any resonant blend of adjacent instruments, and i
> > already have a modicum of success in terms of 'more lifelike' response
> > using this method. I'm also using orchestral samples here, not a live
> > orchestra, so i'm keen to explore just how far we can get down the
> > 'real' road, before limitations prevail.
>
> i see.
>
> > As an aside to this, the VSL orchestral sample library team have already
> > started a project not dissimilar to this, called MIR, so the concept is
> > not just mine, or even theirs... :)
> >
> >
> > I knew i was kinda hopeful when i asked about cutting an impulse into
> > chunks, so i'm not surprised at all.
> >
> > Now to get this Amb problem sorted out.
>
> yeah, i'd be interested to hear how it turns out. if you find the time,
> post your findings to LAU.
>
> fwiw, i'm just working on a somewhat related project. i have a
> multi(close)miked recording of an organ concert with three spatially
> discrete organs and a few hamasaki signals, and i'm trying to shoehorn
> those into a spatially correct and pleasant 2nd order ambisonic mix in
> full 3d. i've taken a leaf from your book and i'm applying individual
> delays to each microphone to correct the distance to the (virtual)
> listening position i'm mixing for, and i've measured the source
> positions in azimuth and elevation to be able to pan them correctly.
> results are quite enjoyable so far, but i hope to be able to bribe the
> organist to play some excerpts for me again, so that i can take a
> soundfield recording for reference... the results will be presented in a
> paper on LAC 2009.
>
> have you considered publishing your results as well? the lac paper
> deadline is still open iirc.
>
> regards,
>
> jörn
>
>
>
>
> > Alex.
> >
> >
> > On Sun, Jan 4, 2009 at 1:32 PM, Jörn Nettingsmeier
> > <nettings@email-addr-hidden-hochschule.de
> > <mailto:nettings@email-addr-hidden-hochschule.de>> wrote:
> >
> > alex stone wrote:
> > > Ok, this might be a bit of curly question, and as i don't know if
> this
> > > is possible, either valid or not.
> > >
> > > The subject is placement, and pertains to orchestral recording.
> > (My own
> > > work composed within the box with linuxsampler, from midi in RG,
> and
> > > recorded in Ardour.)
> > >
> > > I'd like to place my instruments as close as possible to an
> orchestral
> > > setup, in terms of recorded sound. That is, once i've recorded,
> > i'd like
> > > to use convolution and other tools to 'correctly' place instruments
> > > within the overall soundscape.
> > >
> > >
> > > example:
> > >
> > > With the listener sitting 10 metres back from the stage, and
> > facing the
> > > conductor (central) my 1st violins are on the listener's left.
> Those
> > > first violins occupy a portion of the overall soundscape from a
> point
> > > approximately 2 metres to the left of the conductor, to an outside
> > left
> > > position, approximately 10 metres from the conductor, and with 8
> > desks
> > > (2 players per desk) about 4 metres deep at the section's deepest
> > > point, in the shape of a wedge, more or less. That's the pan width
> of
> > > the section.
> > >
> > > Now as i understand it, a metre represents approximately 3ms, so
> > > calculating the leading edge of the section across the stage as
> > 'zero',
> > > the first violin players the furthest in depth from the front of
> the
> > > stage, should, in theory, (and i know this is approximate only, as
> > i sat
> > > as a player in orchestras for some years, and understand the
> > instinctive
> > > timing compensation that goes on) play about 12ms later than those
> at
> > > the front. Using the ears, and experimenting, this actually
> translates
> > > as about 6ms, before the sound becomes unrealistic, using layered
> > violin
> > > samples, both small section and solo. (highly subjective i know,
> but i
> > > only have my own experience as a player and composer to fall back
> > on here.)
> >
> > make sure that you are using different samples for each desk if you
> use
> > individual delays, otherwise you will introduce comb filtering
> > artefacts.
> > but i doubt these delays will have any perceptible benefit.
> >
> > > A violin has it's own unique characteristics in distribution of
> sound
> > > emanating from the instrument. The player sits facing the
> > conductor, and
> > > the bulk of the overall sound goes up, at an angle, at more or less
> > > 30degrees towards the ceiling to a 'point' equivalent to almost
> > directly
> > > over the listener's right shoulder. Naturally the listener
> > 'hears' the
> > > direct sound most prominently, (both with ears, and the 'visual
> > > perception' he gains from listening with his eyes.) Secondly, the
> > violin
> > > also sounds, to a lesser degree, downwards, and in varying
> > proportions,
> > > in a reasonably 'spherical' sound creation model, with the possible
> > > exception of the sound hitting the player's body, and those in his
> > > immediate vicinity. (and other objects, like stands, sheet music,
> etc,
> > > all playing a part too.)
> > >
> > > I've experimented with this quite a bit, and the best result seems
> to
> > > come from a somewhat inadequate, but acceptable, computational
> model
> > > based on using, you guessed it, the orchestral experience ears.
> > >
> > > So i take one 'hall' impulse, and apply it to varying degrees,
> mixed
> > > with as precise a pan model as possible (and i use multiple desks
> to
> > > layer with,more or less, so there's a reasonably accurate
> > depiction of a
> > > pan placed section, instead of the usual pan sample model of either
> > > shifting the section with a stereo pan, or the inadequate right
> > channel
> > > down, left channel up method.)
> >
> > phew! ambitious!
> >
> > > to make this more complicated (not by intent, i assure you), i'm
> > > attempting to add a degree of pseudo mike bleed, from my 1st
> violins,
> > > into the cellos sitting deeper on the stage, and in reduced amounts
> to
> > > the violas and second violins sitting on the other side of the
> > digital
> > > stage.
> > >
> > > All of this is with the intent of getting as as lifelike a sound as
> > > possible from my digital orchestra.
> >
> > why simulate mike bleed? i thought you were after creating a "true"
> > orchestra sound, not one including all unwanted multi-miking
> > artefacts... i'd rather concentrate on instruments and room.
> >
> > > The questions:
> > >
> > > In terms of convolution, , can i 'split' a convolution impulse
> > with some
> > > sort of software device, as to emulate the varying degrees of
> > spherical
> > > sound from instruments as described above?
> >
> > you could get a b-format response from every place in the orchestra
> > (with all other musicians sitting there, for damping), and then
> convolve
> > it with the violin (which would also have to be shoehorned to
> b-format,
> > simulating the desired radiation pattern).
> > but if you have the room and the orchestra, you might as well let
> them
> > play your stuff ;)
> >
> > > So, one impulse (I use Jconv by default, as it does a great job,
> far
> > > better than most gui bloated offerings in the commercial world)
> > that can
> > > be, by way of sends, and returns, be 'split' or manipulated not
> > only in
> > > terms of length of impulse, but fed as 'panned' so as to put more
> > > impulse 'up', less impulse 'down' and just a twitch of impulse
> > 'forward'
> > > of the player, with near enough to none on the sound going back
> > into the
> > > player.
> >
> > i'm not sure i understand 100%, but you might want to look into
> > ambisonics for that. ardour can do it just fine, all you need to do
> is
> > bypass the panners and use fons' AMB plugins instead. as to target
> > format, you could use UHJ stereo. if you desire 5.1, you might want
> to
> > consider working in second order ambisonics.
> >
> > > I've written this rather clumsily, but i hope some of you experts
> may
> > > understand what i'm trying to achieve here.
> > > Can the impulse be split down it's middle, separating left from
> right,
> > > aurally speaking, and if this is possible, can i split the impulse
> > into
> > > 'wedges' emulating that sphere i wrote of, more or less?
> >
> > no, i don't think so. you will need a spatial impulse response. the
> > simplest way to obtain one is to use a soundfield microphone (or a
> > tetramic, for that matter).
> >
> > > if there's a way to do this, then i'm all ears, as my mike bleed
> > > experiments suffer from a 'generic' impulse per section affecting
> > > everything to the same degree, including the instruments bled in. I
> > > should note here, this is not about gain, but a wedge of impulse,
> cut
> > > out of the overall chunk, that represents a 'window' or pan section
> of
> > > the whole.
> >
> > i still don't understand why you're after "mike bleed".
> >
> > > I suppose an analogy for the chunk of impulse idea would be to
> > stretch a
> > > ribbon across a stage, and cut a metre out of the middle. That
> metre
> > > would be the bit i'd use, as a portion of the whole, in an aural
> > > soundscape, to manipulate, or place, instruments, to a finer
> > degree, in
> > > the attempt to create a more realistic '3d' effect for the
> listener.
> > > That metre along with other cut out sections of the impulse
> soundscape
> > > could help me introduce a more....'human' element to a layered
> > > instrument section.
> >
> > yeah, well, *if* we had a way of capturing a sound field completely
> over
> > such a vast area, we would all be very happy indeed. it can be
> recreated
> > using wave field synthesis or very high order ambisonics, but
> currently
> > there is no way of capturing it, other than measuring a set of
> > individual points in that sound field.
> >
> >
> > hth,
> >
> > jörn
> >
> >
> >
> >
>
>

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Received on Tue Jan 13 20:15:02 2009