[Sursound] distance perception in virtual environments

[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

[Sursound] distance perception in virtual environments

[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 for HOA

You have to simulate early reflections and a reverb pattern appropriate to 
source distance.  MAG has a paper on this under "Distance Panners" from an idea 
by Peter Craven.

Real Life Distance Perception is TERRIBLE under (near) anechoic conditions.  I 
recorded Paul Robinson's band at the IMAX theatre in Bradford.  They were 
providing music for a festival of silent movies.  Even after 5 days, we still 
found it disconcerting in that very dead environment.  Someone would call you 
from the door 20m away and you thought they were beside you.


___
Sursound mailing list
Sursound@music.vt.edu
https://mail.music.vt.edu/mailman/listinfo/sursound

Re: [Sursound] rf interference

[Richard Lee]

RFI protection is a complex & little understood subject. "Pro" mikes differ 
hugely in their susceptibility.  There are famous mikes from famous names which 
are terrible.  The preamp input also needs to be RFI proofed.

Though I lust after a SD 788, Jim Brown says its input socket shells may not be 
connected to chassis.  ".. I've seen it in connectors built into very good 
quality preamps and mics from a variety of manufacturers.  So far the list 
includes Audio-Technica, Mackie, Neumann, Sound Devices and Tascam."  Probably 
worth contacting Sound Devices if you own one as I'm sure they will have a cure 
or retrofit if they know of the problem.

Pin_1_Revisited_Part_2.pdf  from Syn-Aud-Con

A long unbalanced cable is just asking for trouble.  Len explicitly recommends 
AGAINST using the extension in bad RFI areas.

A (possible) cheap cure worth trying on unbalanced lines is the clip on Ferrite 
sleeves often found on computer cables.

http://jaycar.com.au/productView.asp?ID=LF1294&keywords=LF-1294&form=KEYWORD

Even better if you can take a turn round the Ferrite.  You need them at both 
ends as close to the connector as possible.

Do let us know what you tried even if it doesn't work.  Is it AM radio you are 
getting?

PS  The Pin 1 problem is RFI getting in on the shields.
___
Sursound mailing list
Sursound@music.vt.edu
https://mail.music.vt.edu/mailman/listinfo/sursound

Re: [Sursound] Powering the DR-680

[David Worrall]

Thanks John, I see. so it plugs into the power socket.
(I've just purchased a DR-680 in anticipation of getting a couple of Len's 
Little Marvels for field recording, so was wondering.)
Neat machine!

David
On 18/04/2011, at 10:41 AM, John Leonard wrote:

> David,
> 
> The DR-680 is powered either by eight AA cells, or via a 12v DC input from a 
> wall-wart PSU or an external battery back. The pack I'm using provides 12 
> volts, so just plugs straight in.
> 
> Regards,
> 
> John
> 
> On 18 Apr 2011, at 01:24, David Worrall wrote:
> 
>> Hi John,
>> Does this unit plug into the AC socket on the DR-680 or how?
> 
> ___
> Sursound mailing list
> Sursound@music.vt.edu
> https://mail.music.vt.edu/mailman/listinfo/sursound

_
Dr David Worrall
Experimental Composer, Polymedia
Adjunct Research Fellow, Australian National University
david.worr...@anu.edu.au
Board Member, International Community for Auditory Display
Regional Editor, Organised Sound (CUP) 
IT Project Manager, Music Council of Australia 
worrall.avatar.com.au   sonification.com.au
mca.org.au  musicforum.org.au
T : +61 (0)2 61.61.95.22M: +61 (0)4.02.28.36.90



-- next part --
An HTML attachment was scrubbed...
URL: 

___
Sursound mailing list
Sursound@music.vt.edu
https://mail.music.vt.edu/mailman/listinfo/sursound

Re: [Sursound] Powering the DR-680

[John Leonard]

David,

The DR-680 is powered either by eight AA cells, or via a 12v DC input from a 
wall-wart PSU or an external battery back. The pack I'm using provides 12 
volts, so just plugs straight in.

Regards,

John

On 18 Apr 2011, at 01:24, David Worrall wrote:

> Hi John,
> Does this unit plug into the AC socket on the DR-680 or how?

___
Sursound mailing list
Sursound@music.vt.edu
https://mail.music.vt.edu/mailman/listinfo/sursound

Re: [Sursound] rf interference

[Bill de Garis]

The (black) InstaSnake with the PPA's zip tied to the base of the mic stand is 
reasonably unobtrusive and the shielded CAT5 almost invisible (dep on the colour of the 
floor).

Bill

On 17/04/2011 2:59 p.m., Fons Adriaensen wrote:

On Sun, Apr 17, 2011 at 05:44:08PM -0400, Jascha Narveson wrote:


I was using the 6-foot extension cable yesterday.  I didn't try it today, so I 
can't comment on whether swapping out the cable today affected the RFI, or if 
was just a different day and wouldn't've happened in any case.


RF interference seems to be a recurrent problem with the Tetramic.
I've experienced it on many occasions, and almost always leaving
out the extension cable has removed or at least reduced the
interference. But it leaves you with the four PPAs and four
standard mic cables gaffer-taped to the mic stand - not a view
most concert audiences do appreciate.

I've been considering to modify the mic to have a short but more
solid and better screened fixed cable terminating in a full-size
6-pin XLR, instead of the mini-xlr and the all too delicate
extension and breakout cables.

Ciao,


___
Sursound mailing list
Sursound@music.vt.edu
https://mail.music.vt.edu/mailman/listinfo/sursound

Re: [Sursound] Powering the DR-680

[David Worrall]

Hi John,
Does this unit plug into the AC socket on the DR-680 or how?

David
On 18/04/2011, at 9:44 AM, John Leonard wrote:

> Update - that's three 8 GB cards with four channels of phantom power turned 
> on and 96/24 recording settings. Now, anyone want almost six hours of traffic 
> recording outside our flat?
> 
> The battery was still providing power when I terminated the session just now, 
> so not bad going at all. About five and a half hours in all from a fully 
> charged unit.
> 
> Regards,
> 
> 
> On 17 Apr 2011, at 22:45, John Leonard wrote:
> 
>> Folks,
>> 
>> I'm in the middle of doing some tests on battery-powering the Tascam DR-680, 
>> having been pretty shocked by how little time a set of Duracell Ultra AAs 
>> lasted (about an hour and a half) and am having pretty good results with the 
>> badge-engineered Tekkeon unit, which is sometimes available in the UK as the 
>> Prestigio Power Bank 501. I set it up to record four tracks at 96/24 with an 
>> SPS-200-SB and just left it running. So far I've filled two 8 GB cards 
>> (that's three hours, fifty minutes) and it's still chugging along quite 
>> happily, with one light down on its battery charge indicator. 
> 
> ___
> Sursound mailing list
> Sursound@music.vt.edu
> https://mail.music.vt.edu/mailman/listinfo/sursound



_
Dr David Worrall
Adjunct Research Fellow, Australian National University
david.worr...@anu.edu.au
Board Member, International Community for Auditory Display
Regional Editor, Organised Sound (CUP) 
Projects Officer, Music Council of Australia 
worrall.avatar.com.au   sonification.com.au
mca.org.au  musicforum.org.au


-- next part --
An HTML attachment was scrubbed...
URL: 

___
Sursound mailing list
Sursound@music.vt.edu
https://mail.music.vt.edu/mailman/listinfo/sursound

Re: [Sursound] Powering the DR-680

[David Worrall]

Any chance of making it available non-privately, Brian?

David
On 18/04/2011, at 10:11 AM, Brian wrote:

> An HTML attachment was scrubbed...
> URL: 
> <https://mail.music.vt.edu/mailman/private/sursound/attachments/20110417/e37d44e8/attachment.html>
> ___
> Sursound mailing list
> Sursound@music.vt.edu
> https://mail.music.vt.edu/mailman/listinfo/sursound

_
Dr David Worrall
Adjunct Research Fellow, Australian National University
david.worr...@anu.edu.au
Board Member, International Community for Auditory Display
Regional Editor, Organised Sound (CUP) 
Projects Officer, Music Council of Australia 
worrall.avatar.com.au   sonification.com.au
mca.org.au  musicforum.org.au

-- next part --
An HTML attachment was scrubbed...
URL: 
<https://mail.music.vt.edu/mailman/private/sursound/attachments/20110418/a00d6b64/attachment.html>
___
Sursound mailing list
Sursound@music.vt.edu
https://mail.music.vt.edu/mailman/listinfo/sursound

Re: [Sursound] Powering the DR-680

[Brian]

An HTML attachment was scrubbed...
URL: 
<https://mail.music.vt.edu/mailman/private/sursound/attachments/20110417/e37d44e8/attachment.html>
___
Sursound mailing list
Sursound@music.vt.edu
https://mail.music.vt.edu/mailman/listinfo/sursound

Re: [Sursound] Powering the DR-680

[John Leonard]

Update - that's three 8 GB cards with four channels of phantom power turned on 
and 96/24 recording settings. Now, anyone want almost six hours of traffic 
recording outside our flat?

The battery was still providing power when I terminated the session just now, 
so not bad going at all. About five and a half hours in all from a fully 
charged unit.

Regards,


On 17 Apr 2011, at 22:45, John Leonard wrote:

> Folks,
> 
> I'm in the middle of doing some tests on battery-powering the Tascam DR-680, 
> having been pretty shocked by how little time a set of Duracell Ultra AAs 
> lasted (about an hour and a half) and am having pretty good results with the 
> badge-engineered Tekkeon unit, which is sometimes available in the UK as the 
> Prestigio Power Bank 501. I set it up to record four tracks at 96/24 with an 
> SPS-200-SB and just left it running. So far I've filled two 8 GB cards 
> (that's three hours, fifty minutes) and it's still chugging along quite 
> happily, with one light down on its battery charge indicator. 

___
Sursound mailing list
Sursound@music.vt.edu
https://mail.music.vt.edu/mailman/listinfo/sursound

Re: [Sursound] rf interference

[Jascha Narveson]

Interesting!  I'd be curious to know where you get with that.  What would you 
do about the PPAs, though?  My impression is that they need to be part of the 
signal chain, and that sending straight 48v phantom power to the TetraMic is 
somehow bad. 

cheers,

j

On Apr 17, 2011, at 5:59 PM, Fons Adriaensen wrote:

> On Sun, Apr 17, 2011 at 05:44:08PM -0400, Jascha Narveson wrote:
> 
>> I was using the 6-foot extension cable yesterday.  I didn't try it today, so 
>> I can't comment on whether swapping out the cable today affected the RFI, or 
>> if was just a different day and wouldn't've happened in any case.
> 
> RF interference seems to be a recurrent problem with the Tetramic.
> I've experienced it on many occasions, and almost always leaving
> out the extension cable has removed or at least reduced the 
> interference. But it leaves you with the four PPAs and four
> standard mic cables gaffer-taped to the mic stand - not a view
> most concert audiences do appreciate.
> 
> I've been considering to modify the mic to have a short but more
> solid and better screened fixed cable terminating in a full-size
> 6-pin XLR, instead of the mini-xlr and the all too delicate 
> extension and breakout cables.
> 
> Ciao,
> 
> -- 
> FA
> 
> 
> 
> ___
> Sursound mailing list
> Sursound@music.vt.edu
> https://mail.music.vt.edu/mailman/listinfo/sursound
> 

___
Sursound mailing list
Sursound@music.vt.edu
https://mail.music.vt.edu/mailman/listinfo/sursound

Re: [Sursound] distance perception in virtual environments

[Ralph Glasgal]

For relatively nearby distance detection such as the buzzing bee or whispering 
or conversation (versus more distant sources such as in a concert hall), one 
needs to deliver interaural level differences on the order of 10 ot 20 dB with 
the corresponding ITD of up to 700 microseconds.  (If the sources and speakers 
are relatively centered then we can ignore the pinna distance detection 
problem.)  At the moment I believe only the Choueiri BACCH dummy head recording 
and crosstalk cancellation method can routinely deliver this magnitude of ILD 
over the full range of frequencies.  If you are synthesizing the ILD in 
your virtual signals then you don't need to use a dummy head or an Ambiophone.  
Of course, this ILD seems to apply only for distances to sources at the sides 
of the head but in practice extreme XTC and thus real binaural ITD provides for 
proximity at all frontal angles in the horizontal plane as in everyday 
hearing.    
 
RACE, if carefully implemented with directional nearfield speakers, can get up 
to about 10 dB or more ILD and you might try this since it is easier (cheaper) 
than using any of the other crosstalk cancelling or WFS or HOA methods.  There 
is no question that Ambiophonic users report enhanced depth perception when 
listening to ordinary music or the commercially available earphone type 
binaural recordings but you may want more than this for what you are doing so 
you should tweak the normal Ambiophonic methodology to optimize ILD capture and 
reproduction.
 
Ralph Glasgal
www.ambiophonics.org    

From: Junfeng Li 
To: Surround Sound discussion group 
Sent: Saturday, April 16, 2011 9:28 PM
Subject: [Sursound] distance perception in virtual environments

Dear list,

I am now wondering how to subjectively evaluate distance perception in
virtual environments which might be synthesized using WFS or HOA (high-order
ambisonics). In my experiments, the sounds were synthesized at different
distances and presented to listeners for distance discrimination. However,
the listener cannot easily perceive the difference in distance between these
sounds.

Anyone can share some ideas or experiences in distance perception
experiments? or share some references on this issue?

Thank you so much.

Best regards,
Junfeng
-- next part --
An HTML attachment was scrubbed...
URL: 
<https://mail.music.vt.edu/mailman/private/sursound/attachments/20110417/64a7d936/attachment.html>
___
Sursound mailing list
Sursound@music.vt.edu
https://mail.music.vt.edu/mailman/listinfo/sursound
-- next part --
An HTML attachment was scrubbed...
URL: 
<https://mail.music.vt.edu/mailman/private/sursound/attachments/20110417/da4e9255/attachment.html>
___
Sursound mailing list
Sursound@music.vt.edu
https://mail.music.vt.edu/mailman/listinfo/sursound

Re: [Sursound] rf interference

[Fons Adriaensen]

On Sun, Apr 17, 2011 at 05:44:08PM -0400, Jascha Narveson wrote:

> I was using the 6-foot extension cable yesterday.  I didn't try it today, so 
> I can't comment on whether swapping out the cable today affected the RFI, or 
> if was just a different day and wouldn't've happened in any case.

RF interference seems to be a recurrent problem with the Tetramic.
I've experienced it on many occasions, and almost always leaving
out the extension cable has removed or at least reduced the 
interference. But it leaves you with the four PPAs and four
standard mic cables gaffer-taped to the mic stand - not a view
most concert audiences do appreciate.

I've been considering to modify the mic to have a short but more
solid and better screened fixed cable terminating in a full-size
6-pin XLR, instead of the mini-xlr and the all too delicate 
extension and breakout cables.

Ciao,

-- 
FA



___
Sursound mailing list
Sursound@music.vt.edu
https://mail.music.vt.edu/mailman/listinfo/sursound

[Sursound] Powering the DR-680

[John Leonard]

Folks,

I'm in the middle of doing some tests on battery-powering the Tascam DR-680, 
having been pretty shocked by how little time a set of Duracell Ultra AAs 
lasted (about an hour and a half) and am having pretty good results with the 
badge-engineered Tekkeon unit, which is sometimes available in the UK as the 
Prestigio Power Bank 501. I set it up to record four tracks at 96/24 with an 
SPS-200-SB and just left it running. So far I've filled two 8 GB cards (that's 
three hours, fifty minutes) and it's still chugging along quite happily, with 
one light down on its battery charge indicator. 

If anyone in the UK's interested, Amazon currently have one in stock for a 
penny under £100 and it comes with a smart leather case and a nice little 
velvet bag full of connection tips. It has a switchable output voltage, which 
goes up to 19 volts, and apparently a 10 Amp Hour capacity. 

As I say, as far as I know, it's a badge engineered version of the Tekkeon 
MP3450, which B&H have for US$124.

Next step is a set of Engergizer 2450 mA/Hr rechargeables, which I'm charging 
overnight now.

I'll report back once I've done the test.

Regards,

John

P.S. Hello, Neil - hope the restaurant's doing well - I've read some rave 
reviews for it! Can I interest you in some Spitfire surround material for 
special occasions?


___
Sursound mailing list
Sursound@music.vt.edu
https://mail.music.vt.edu/mailman/listinfo/sursound

Re: [Sursound] rf interference

[Jascha Narveson]

Hi, David -

I was using the 6-foot extension cable yesterday.  I didn't try it today, so I 
can't comment on whether swapping out the cable today affected the RFI, or if 
was just a different day and wouldn't've happened in any case.

cheers,

j


On Apr 17, 2011, at 5:10 PM, David Worrall wrote:

> Hi Jascha,
> What length extension cable were you using?
> And does anyone have any experience of the comparative differences between 
> the the different lengths?
> 
> David
> On 18/04/2011, at 6:30 AM, Jascha Narveson wrote:
> 
>> 
>> Hi, Bill -
>> 
>> Yep - I skipped the extension cable today and just had the mic go from the 
>> breakout cable to the PPAs, and today's recording didn't turn up with any 
>> RFI, at least when I played back the first couple of minutes of the test 
>> recording.  Hopefully the remainder will be RFI-free, as well.
>> 
>> Thanks, surround sound list.
>> 
>> cheers,
>> 
>> j
>> 
>> 
>> On Apr 16, 2011, at 5:56 PM, Bill de Garis wrote:
>> 
>>> I have the radio pick up problem with my Tetramic.
>>> I find it is better to put the 4 XLR adaptors into my 4x3ft XLR cables and 
>>> then plug the XLR cables into my MOTU Traveller rather than use one of Lens 
>>> extension cables and plug the adaptors directly into the Traveller.
>>> If I need distance I use a couple of InstaSnakes and shielded CAT5.
>>> Radio pickup is still a problem in some locations though.
>>> I tried wrapping multiple layers of heavy kitchen aluminium foil over the 
>>> adapters after zip-tying them to the handle of my Rycote blimp.
>>> Worked OK in the kitchen, but nowhere else.  :o)
>>> 
>>> Bill
>>> 
>>> On 16/04/2011 12:36 p.m., Jascha Narveson wrote:
 
 Hello, once again, surround list -
 
 My apologies for the continued emails from my end - as you can tell, I'm 
 trying to muddle through some location recording this weekend, and am 
 running in to things I've never dealt with before.  To whit:
 
 I've just come back from recording in Times Square and discovered that I 
 was picking up the radio.  I'm using a TetraMic, and I'm guessing that the 
 6' extension cable that goes from the mic to the break-out cable might be 
 the weak link, as it looks rather thin and is probably unshielded.  From 
 the PPAs I have four 3-foot XLR cables that are then going in to the 788T, 
 so they might be part of the problem, as well.
 
 I know that in picking Times Square as a recording subject I'm walking in 
 to one of the heavier RF zones in the city, but I'm hoping that somebody 
 here might have some tips of things I can try to work around it...?  Is 
 there some way I can shield the cables in a d.i.y. fashion, for instance?
 
 thanks yet again,
 
 - jascha
 
> 
> 
> Dr David Worrall
> Adjunct Research Fellow, Australian National University
> david.worr...@anu.edu.au
> Board Member, International Community for Auditory Display
> Regional Editor, Organised Sound (CUP) 
> Projects Officer, Music Council of Australia 
> worrall.avatar.com.au sonification.com.au
> mca.org.aumusicforum.org.au
> 
> 
> -- next part --
> An HTML attachment was scrubbed...
> URL: 
> 
> ___
> Sursound mailing list
> Sursound@music.vt.edu
> https://mail.music.vt.edu/mailman/listinfo/sursound
> 

___
Sursound mailing list
Sursound@music.vt.edu
https://mail.music.vt.edu/mailman/listinfo/sursound

Re: [Sursound] distance perception in virtual environments

[Fons Adriaensen]

On Sun, Apr 17, 2011 at 09:28:28AM +0800, Junfeng Li wrote:

> I am now wondering how to subjectively evaluate distance perception in
> virtual environments which might be synthesized using WFS or HOA (high-order
> ambisonics). In my experiments, the sounds were synthesized at different
> distances and presented to listeners for distance discrimination. However,
> the listener cannot easily perceive the difference in distance between these
> sounds.

No surprise really. 

There is very little difference between the _direct_ sound of a source
at e.g. 2 m distance, and one at 20 m. Except for *very* close sources
a static receiver having the size of a human head has almost no
information to detect the curvature of the wavefront and hence the
distance of the source. In anechoic conditions it's near impossible to
detect distance, except again for very close sources, or by implicitly
assuming some standard loudness for the source, e.g. a human voice 
which has a strong correlation between loudness and timbre.

As others have already pointed out, distance perception depends in
practice almost entirely on interaction of the sound source with the
environment: the relative level of reverberation and direct sound,
and the delays and levels of early reflections. In a virtual environment
created by HOA or WFS you have to artificially recreate those as well,
otherwise the acoustics of the listening space will dominate and the
apparent distance of any reproduced sound will be the distance to the
speaker.

Ciao,

-- 
FA

___
Sursound mailing list
Sursound@music.vt.edu
https://mail.music.vt.edu/mailman/listinfo/sursound

Re: [Sursound] distance perception in virtual environments

[jim moses]

That's an interesting question. The environment you're working in for
synthesis could matter quite a bit. That is, if your working in, or
simulating, an environment with little reverberation it is harder to judge
distance since direct-to-reflected energy ratio is an important cue. The
other important cue is timbre detail - especially high frequencies. But this
requires the listener be familiar with the sound source to be able to
discriminate. Try testing with spoken voice.

I can't think of any research of the top of my head (especially for
multi-channel environments). It is certainly well known that controlling
high frequencies and direct/reflected ratio is important for distance
perception in stereo mixing - but even there that's usually a relative, or
comparative judgment, of one sound source appear vaguely 'behind' another.
Not so much an absolute judgment that you might want for a virtual
environment.

jim

On Sat, Apr 16, 2011 at 9:28 PM, Junfeng Li wrote:

> Dear list,
>
> I am now wondering how to subjectively evaluate distance perception in
> virtual environments which might be synthesized using WFS or HOA
> (high-order
> ambisonics). In my experiments, the sounds were synthesized at different
> distances and presented to listeners for distance discrimination. However,
> the listener cannot easily perceive the difference in distance between
> these
> sounds.
>
> Anyone can share some ideas or experiences in distance perception
> experiments? or share some references on this issue?
>
> Thank you so much.
>
> Best regards,
> Junfeng
> -- next part --
> An HTML attachment was scrubbed...
> URL: <
> https://mail.music.vt.edu/mailman/private/sursound/attachments/20110417/64a7d936/attachment.html
> >
> ___
> 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)
-- next part --
An HTML attachment was scrubbed...
URL: 
<https://mail.music.vt.edu/mailman/private/sursound/attachments/20110417/5157390f/attachment.html>
___
Sursound mailing list
Sursound@music.vt.edu
https://mail.music.vt.edu/mailman/listinfo/sursound

Re: [Sursound] rf interference

[David Worrall]

Hi Jascha,
What length extension cable were you using?
And does anyone have any experience of the comparative differences between the 
the different lengths?

David
On 18/04/2011, at 6:30 AM, Jascha Narveson wrote:

> 
> Hi, Bill -
> 
> Yep - I skipped the extension cable today and just had the mic go from the 
> breakout cable to the PPAs, and today's recording didn't turn up with any 
> RFI, at least when I played back the first couple of minutes of the test 
> recording.  Hopefully the remainder will be RFI-free, as well.
> 
> Thanks, surround sound list.
> 
> cheers,
> 
> j
> 
> 
> On Apr 16, 2011, at 5:56 PM, Bill de Garis wrote:
> 
>> I have the radio pick up problem with my Tetramic.
>> I find it is better to put the 4 XLR adaptors into my 4x3ft XLR cables and 
>> then plug the XLR cables into my MOTU Traveller rather than use one of Lens 
>> extension cables and plug the adaptors directly into the Traveller.
>> If I need distance I use a couple of InstaSnakes and shielded CAT5.
>> Radio pickup is still a problem in some locations though.
>> I tried wrapping multiple layers of heavy kitchen aluminium foil over the 
>> adapters after zip-tying them to the handle of my Rycote blimp.
>> Worked OK in the kitchen, but nowhere else.  :o)
>> 
>> Bill
>> 
>> On 16/04/2011 12:36 p.m., Jascha Narveson wrote:
>>> 
>>> Hello, once again, surround list -
>>> 
>>> My apologies for the continued emails from my end - as you can tell, I'm 
>>> trying to muddle through some location recording this weekend, and am 
>>> running in to things I've never dealt with before.  To whit:
>>> 
>>> I've just come back from recording in Times Square and discovered that I 
>>> was picking up the radio.  I'm using a TetraMic, and I'm guessing that the 
>>> 6' extension cable that goes from the mic to the break-out cable might be 
>>> the weak link, as it looks rather thin and is probably unshielded.  From 
>>> the PPAs I have four 3-foot XLR cables that are then going in to the 788T, 
>>> so they might be part of the problem, as well.
>>> 
>>> I know that in picking Times Square as a recording subject I'm walking in 
>>> to one of the heavier RF zones in the city, but I'm hoping that somebody 
>>> here might have some tips of things I can try to work around it...?  Is 
>>> there some way I can shield the cables in a d.i.y. fashion, for instance?
>>> 
>>> thanks yet again,
>>> 
>>> - jascha
>>> 


Dr David Worrall
Adjunct Research Fellow, Australian National University
david.worr...@anu.edu.au
Board Member, International Community for Auditory Display
Regional Editor, Organised Sound (CUP) 
Projects Officer, Music Council of Australia 
worrall.avatar.com.au   sonification.com.au
mca.org.au  musicforum.org.au


-- next part --
An HTML attachment was scrubbed...
URL: 

___
Sursound mailing list
Sursound@music.vt.edu
https://mail.music.vt.edu/mailman/listinfo/sursound

Re: [Sursound] rf interference

[Jascha Narveson]

Hi, Bill -

Yep - I skipped the extension cable today and just had the mic go from the 
breakout cable to the PPAs, and today's recording didn't turn up with any RFI, 
at least when I played back the first couple of minutes of the test recording.  
Hopefully the remainder will be RFI-free, as well.

Thanks, surround sound list.

cheers,

j


On Apr 16, 2011, at 5:56 PM, Bill de Garis wrote:

> I have the radio pick up problem with my Tetramic.
> I find it is better to put the 4 XLR adaptors into my 4x3ft XLR cables and 
> then plug the XLR cables into my MOTU Traveller rather than use one of Lens 
> extension cables and plug the adaptors directly into the Traveller.
> If I need distance I use a couple of InstaSnakes and shielded CAT5.
> Radio pickup is still a problem in some locations though.
> I tried wrapping multiple layers of heavy kitchen aluminium foil over the 
> adapters after zip-tying them to the handle of my Rycote blimp.
> Worked OK in the kitchen, but nowhere else.  :o)
> 
> Bill
> 
> On 16/04/2011 12:36 p.m., Jascha Narveson wrote:
>> 
>> Hello, once again, surround list -
>> 
>> My apologies for the continued emails from my end - as you can tell, I'm 
>> trying to muddle through some location recording this weekend, and am 
>> running in to things I've never dealt with before.  To whit:
>> 
>> I've just come back from recording in Times Square and discovered that I was 
>> picking up the radio.  I'm using a TetraMic, and I'm guessing that the 6' 
>> extension cable that goes from the mic to the break-out cable might be the 
>> weak link, as it looks rather thin and is probably unshielded.  From the 
>> PPAs I have four 3-foot XLR cables that are then going in to the 788T, so 
>> they might be part of the problem, as well.
>> 
>> I know that in picking Times Square as a recording subject I'm walking in to 
>> one of the heavier RF zones in the city, but I'm hoping that somebody here 
>> might have some tips of things I can try to work around it...?  Is there 
>> some way I can shield the cables in a d.i.y. fashion, for instance?
>> 
>> thanks yet again,
>> 
>> - jascha
>> 
>> 
>> 
>> ___
>> Sursound mailing list
>> Sursound@music.vt.edu
>> https://mail.music.vt.edu/mailman/listinfo/sursound
>> 
>> 
> ___
> Sursound mailing list
> Sursound@music.vt.edu
> https://mail.music.vt.edu/mailman/listinfo/sursound
> 

___
Sursound mailing list
Sursound@music.vt.edu
https://mail.music.vt.edu/mailman/listinfo/sursound

Re: [Sursound] distance perception in virtual environments

[Markus Noisternig]

Hi, 

Gavin Kearney et al have presented their work on "Depth perception in 
interactive virtual acoustic environments using higher order ambisonic 
soundfields" at the Ambisonics'11 symposium in Paris; the article is available 
online at http://ambisonics10.ircam.fr/drupal/?q=proceedings/o6

Best, 
Markus

On 17 avr. 2011, at 19:38, Dave Hunt wrote:

> Hi,
> 
>> Date: Sun, 17 Apr 2011 09:28:28 +0800
>> From: Junfeng Li 
>> Subject: [Sursound] distance perception in virtual environments
>> 
>> Dear list,
>> 
>> I am now wondering how to subjectively evaluate distance perception in
>> virtual environments which might be synthesized using WFS or HOA (high-order
>> ambisonics). In my experiments, the sounds were synthesized at different
>> distances and presented to listeners for distance discrimination. However,
>> the listener cannot easily perceive the difference in distance between these
>> sounds.
>> 
>> Anyone can share some ideas or experiences in distance perception
>> experiments? or share some references on this issue?
>> 
>> Thank you so much.
>> 
>> Best regards,
>> Junfeng
> 
> Change in amplitude with distance should be perceptible fairly easily, but on 
> its own would just sound the same but quieter, or louder. High frequency 
> absorption by the air is only really perceptible when the distance is fairly 
> large, though this effect could be exaggerated for artistic purposes. The 
> lateness of arrival of sound from distant objects is not directly perceptible 
> unless there is something visible (e.g. lightning and thunder).
> 
> Reverberation definitely gives perceptible distance effects. More distant 
> sources are more reverberant. The amplitude of the direct signal should 
> decrease with distance (inverse square law, or some similar law), while the 
> amplitude of the reflected and reverberant signal would remain fairly 
> constant or decrease less rapidly with distance than that of the direct 
> signal. It is the ratio of direct to reverberant sound that is important.
> 
> John Chowning's 1971 paper "The Simulation of Moving Sound Sources" is a good 
> early consideration of how to synthesise distance.
> 
> Of course the reported result will depend on the listener, who may not be 
> used to analysing sound for these effects.
> 
> Ciao,
> 
> Dave
> 
> ___
> Sursound mailing list
> Sursound@music.vt.edu
> https://mail.music.vt.edu/mailman/listinfo/sursound
> 

___
Sursound mailing list
Sursound@music.vt.edu
https://mail.music.vt.edu/mailman/listinfo/sursound

Re: [Sursound] distance perception in virtual environments

[Dave Hunt]

Hi,


Date: Sun, 17 Apr 2011 09:28:28 +0800
From: Junfeng Li 
Subject: [Sursound] distance perception in virtual environments

Dear list,

I am now wondering how to subjectively evaluate distance perception in
virtual environments which might be synthesized using WFS or HOA  
(high-order
ambisonics). In my experiments, the sounds were synthesized at  
different
distances and presented to listeners for distance discrimination.  
However,
the listener cannot easily perceive the difference in distance  
between these

sounds.

Anyone can share some ideas or experiences in distance perception
experiments? or share some references on this issue?

Thank you so much.

Best regards,
Junfeng


Change in amplitude with distance should be perceptible fairly  
easily, but on its own would just sound the same but quieter, or  
louder. High frequency absorption by the air is only really  
perceptible when the distance is fairly large, though this effect  
could be exaggerated for artistic purposes. The lateness of arrival  
of sound from distant objects is not directly perceptible unless  
there is something visible (e.g. lightning and thunder).


Reverberation definitely gives perceptible distance effects. More  
distant sources are more reverberant. The amplitude of the direct  
signal should decrease with distance (inverse square law, or some  
similar law), while the amplitude of the reflected and reverberant  
signal would remain fairly constant or decrease less rapidly with  
distance than that of the direct signal. It is the ratio of direct to  
reverberant sound that is important.


John Chowning's 1971 paper "The Simulation of Moving Sound Sources"  
is a good early consideration of how to synthesise distance.


Of course the reported result will depend on the listener, who may  
not be used to analysing sound for these effects.


Ciao,

Dave

___
Sursound mailing list
Sursound@music.vt.edu
https://mail.music.vt.edu/mailman/listinfo/sursound

Re: [Sursound] [ANN] International Conference on Spatial Audio, Nov 10-13 2011, in Detmold, Germany

[Joseph Anderson]

Hello Jörn,

Website?



Joseph Anderson

27 Hungate, Pickering, North Yorkshire, YO18 7DL, UK



On 14 Apr 2011, at 5:55 pm, Jörn Nettingsmeier wrote:

> hi *!
> 
> 
> i think this announcement will be of interest to sursound patrons, so i'm 
> forwarding it on behalf of the entire organization committee. we're in the 
> early stages of planning, so it might make sense to re-visit the website in a 
> few weeks.
> 
> best,
> 
> 
> jörn
> 
> 
> *.*
> 
> 
> ICSA 2011 - International Conference on Spatial Audio
> November 10 - 13, Hochschule für Musik, Detmold
> 
> Organizers:
> 
> Verband Deutscher Tonmeister (VDT), in cooperation with
> Deutsche Gesellschaft für Akustik e.V. (DEGA), and
> European Acoustics Association (EAA).
> 
> Contact/Chair:
> 
> Prof. Dr.-Ing. Malte Kob
> Erich-Thienhaus-Institut
> Neustadt 22, 52756 Detmold
> Mail: icsa2011attonmeister.de
> Phone: +49-(0)5231-975-644
> Fax: +49-(0)5231-975-689





-- next part --
An HTML attachment was scrubbed...
URL: 
<https://mail.music.vt.edu/mailman/private/sursound/attachments/20110417/97bc11ca/attachment.html>
___
Sursound mailing list
Sursound@music.vt.edu
https://mail.music.vt.edu/mailman/listinfo/sursound