Sorry, slipped,
If there are any comb effects, caused by cylinders, it should
certainly be audible at http://klas.telinga.com/demo/walkinginacircle.mp3.
Do you hear any?
I hear a phase shift just before and after 180 degrees, but that is all.
Klas.
At 18:17 2012-08-14, you wrote:
>Hi Klas,
> Thank you for the clarifications,
>
>--- In Klas Strandberg <> wro=
te:
> >
> >
> >
> > >Is the edge (top and bottom) diffraction of the cylinder detectable?
> > >It must cause a comb filter effect depending on the elevation angle?
> >
> > Having flat endings and sharp edges caused some < 0,5 db comb effect
> > when no foam or fake fur was used. Therefore the tops and bottoms of
> > the SSM are rounded.
> > The differences between using a cylinder and using a globe were in
> > all ways less than 1 db and did not show more or less comb effect.
> > Using a rubber suspended alu body, instead of a plastic body,
> > improved unwanted resonances quite audibly.
> > The distance between the cylinders are adjustable about an inch, as
> > well as the sideways angles.
> > For the DIY people, there is an optional arrangement which allows
> > experimenting with distances and angles, jeckling disc's, noses
> or whatever .
>
>A rubber squash ball will also lift 3.5KHz + 6dB which isnt a good
>area, however I noted comb effects using round objects at least 2dB
>comb at 4 and 6 Khz. A cylinder would lift the front with a peak
>on-axis for 0 degrees and for the side at 90 the exact same response
>shows as an anti-node (at the same frequencies) which started to
>notch at 180 degrees. anti-node is controlled by the height of the
>cylinder and freq starting point variable on the cylinder diameter.
>
>The only device I found to give consistently smooth response was a
>log spiral as documented by Neumann eventually computed to a
>triangle for their boundary mics.
>EM172 with small spiral shown below, Blue for 0 degrees, Red for 90
>degrees. (non-anechoic plot) -
>
>http://urlme.net/audio/LS0-90.jpg
>
>For the DIYer's info available on request.
>
>
> >
> > A very similar construction was used for sound effects to a movie
> > which won the prestigious Swedish price for "best film sound 2010."
>
>Was it your design? If so congratulations are in order!!!
>
>BR
>-Mike.
>
>
> >
> > Klas.
> >
> >
> > >The SASS may use this effect by using more surface below the mics
> > >than above, or rather in its nose shape as Gregory has already
> pointed out.
> > >
> > >-M.
> > >
> > >--- In Gregory O'Drobinak
> > ><gmodrobinak@> wrote:
> > > >
> > > > Klas:
> > > >
> > > > The holes in the foam are there for a reason, so that there is
> > > some open space
> > > > to the sides of the PZM capsules. The presence of that hole was
> > > not intended for
> > > > mounting other capsules behind it. The hole is to open up the
> boundary to
> > > > incident sound at the edge of the PZM element.
> > > >
> > > >
> > > > As the mics get close to the nose of the SASS, the response
> > > varies such that
> > > > there will be more attenuation of the high frequencies and the
> > > polar response
> > > > will be changed as well. Hence the "muffled" quality of your
> rig. Had you
> > > > mounted your capsules in the exact spot=C2 of the original PZM mic
> > > capsules, then
> > > > the response should be quite clear.=C2 I believe that someone has
> > > just posted the
> > > > link to the patent so that you can become familiar with the
> > > design parameters.
> > > >
> > > > Do you have a second SASS with 3032s mounted? Can you send us a
> > > picture of their
> > > > mounting details? How about some some sound samples comparing
> > > that particular
> > > > rig to the SSM?
> > > >
> > > > IMHO, I=C2 think that it would be unwise=C2 make the web page (that
> > > you sent us the
> > > > link for) public. The difference between "evaluate" and "hear the
> > > difference" is
> > > > slight. People can take that comparison different ways. Perhaps
> > > it's better not
> > > > to compare the SSM to anything else. I very much enjoyed the
> > > "mailman coming"
> > > > clip, with the fluttering of the birds' wings. Let the SSM stand
> > > on its own.
> > > >
> > > > I noticed that when I did the EQ to correct for the SSM's HF
> > > peaking that it's
> > > > high end was very similar to that of the SASS. Of course, the
> > > localization was
> > > > different. BTW, some of the sound clips had some rather bad
> > > glitches at the
> > > > beginning. What was the cause of this?
> > > >
> > > > Well, I think that you have a fine product here and I wish you
> > > the best of luck
> > > > with it. The only improvement that I could foresee is a
> > > cost-reduced model for
> > > > those of us that are financially impaired.
> > > >
> > > > Best regards,
> > > >
> > > > Greg
> > > >
> > > >
> > > >
> > > >
> > > > ________________________________
> > > > From: Klas Strandberg <telinga@>
> > > > To:
> > > > Sent: Mon, August 13, 2012 4:28:59 PM
> > > > Subject: Re: [Nature Recordists] Re: Miniature Pseudo-SASS Array
> > > >
> > > > =C2
> > > > Vicky, Greg,
> > > >
> > > > Sorry for late answer, Greg!
> > > >
> > > > I got the SASS in 2010 because I wanted a reference when working wi=
th
> > > > the different "Murie" mike's I had. When I got it, brand new, there
> > > > were already two holes in the foam for the microphone capsules. Tha=
t
> > > > is where the 172's are located on the picture.
> > > >
> > > > But quite soon I got more into:
> > > > http://frogrecordist.home.mindspring.com/docs/mod_sass.html
> > > > approved on and used by a lot. The diaphragms are facing out.
> > > > I have also used the SASS with AT3032.
> > > >
> > > > But my intention was not to evaluate "SASS" vs. "SSM", they are
> > > > actually far too different for that. Only hear the difference.
> > > > The most obvious difference is that the SASS is looking forward mor=
e
> > > > than the SSM, which was not a problem for Crown, as it was meant to
> > > > hang on a wall, anyway.
> > > >
> > > > A muffled sound is not wrong, it's a matter of taste. Also,
> > > > headphones make more difference in that aspect than a reasonable
> > > > microphone, not to speak about how hard the headphones are pressing
> > > > against your ears. "Muffled" is a in my mind a word describing
> > > > "characteristics", not "quality".
> > > >
> > > > Klas.
> > > >
> > > > At 22:30 2012-08-13, you wrote:
> > > > >Well-spotted Greg. Looking closely, I certainly agree that Klas's
> > > > >SASS rig has the mics positioned wrongly, they need to be further =
out
> > > > >by half to one inch. And ideally they should have the diaphragms
> > > > >flush with the boundary. I had not been able to grasp why Klas
> > > > >thought of the SASS sound as muffled, I have never found that to b=
e
> > > > >the case with SASS, except occasionally for a sound directly front=
on
> > > > >with a SASS that has a 'square' nose rather than a tapered one.
> > > > >
> > > > >Vicki
> > > > >
> > > > >On 13/08/2012, at 4:21 PM, Gregory O'Drobinak wrote:
> > > > >
> > > > > > Klas, The first thing I noticed is that your modified SASS arra=
y
> > > > > > has the EM172s
> > > > > > [correct me if I'm wrong; that's what they look like] mounted m=
uch
> > > > > > too close to
> > > > > > the 'nose' of the SASS, probably at least one half inch too far=
in.
> > > > > > That very
> > > > > > well could explain some of the "muffled" quality that you descr=
ibe
> > > > > > on that web
> > > > > > page. They are inside the foam of the nose piece, thus any dire=
ct
> > > > > > sound on axis
> > > > > > has to travel through foam, not through free air. This is not g=
ood;
> > > > > > such
> > > > > > deviations can have a negative effect on the array performance.
> > > > > >
> > > > > >
> > > > >Klas had written:
> > > > >
> > > > > > At http://klas.telinga.com/SSM-SASS/ there is a comparison betw=
een
> > > > > > the Telinga SSM and the SASS. I put up this site only to ask a =
few
> > > > > > people that I trust, to say their opinions.
> > > > >
> > > > >
> > > > >
> > > > >------------------------------------
> > > > >
> > > > >"While a picture is worth a thousand words, a
> > > > >sound is worth a thousand pictures." R. Murray Schafer via
> Bernie Krause.
> > > > >
> > > > >Yahoo! Groups Links
> > > > >
> > > > >
> > > > >
> > > > Telinga Microphones, Botarbo,
> > > > S-748 96 Tobo, Sweden.
> > > > Phone & fax int + 295 310 01
> > > > email: telinga@
> > > > website: www.telinga.com
> > > >
> > > >
> > > >
> > > >
> > > >
> > > >
> > > >
> > >
> > >
> > >
> > >------------------------------------
> > >
> > >"While a picture is worth a thousand words, a
> > >sound is worth a thousand pictures." R. Murray Schafer via Bernie Krau=
se.
> > >
> > >Yahoo! Groups Links
> > >
> > >
> > >
> > Telinga Microphones, Botarbo,
> > S-748 96 Tobo, Sweden.
> > Phone & fax int + 295 310 01
> > email:
> > website: www.telinga.com
> >
> >
> >
>
>
>
>------------------------------------
>
>"While a picture is worth a thousand words, a
>sound is worth a thousand pictures." R. Murray Schafer via Bernie Krause.
>
>Yahoo! Groups Links
>
>
>
Telinga Microphones, Botarbo,
S-748 96 Tobo, Sweden.
Phone & fax int + 295 310 01
email:
website: www.telinga.com
|
