Message: 1
Date: Fri, 16 Mar 2012 13:37:48 -0400
From: Daniel Courville<courville.dan...@uqam.ca>
Subject: Re: [Sursound] question about simple equation
To: Sursound<sursound@music.vt.edu>
Message-ID:<cb88efc0.7679%courville.dan...@uqam.ca>
Content-Type: text/plain; charset="ISO-8859-1"
Le 12-03-15 20:01, Giuseppe Silvi a ?crit:
I think the W component of ST450 comes out scaled by sqrt2.
It's -3 dB, revsqrt(2), on the W at the output of the ST450. So, yes,
boosting the W by 3 dB, sqrt(2), at the input of your processor makes
sense. Anyway, it's the way I do it.
// M = (sqrt2 * W) + X; // several clipping problem
M = .5 * ((sqrt2 * W) + X); // without clipping
S = Y
Remember that, globally, you're combining three channels into two
channels, so yes, your output can get over 1, which is a problem at the
DAC, but not internally in Max.
- Daniel
Message: 3
Date: Sat, 17 Mar 2012 05:24:39 -0000
From: Richard Lee<rica...@justnet.com.au>
Subject: Re: [Sursound] question about simple equation
To: 'Surround Sound discussion group'<sursound@music.vt.edu>
Message-ID:<01CD040D.AA671260@edgexp>
Content-Type: text/plain; charset="us-ascii"
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 implementations of this useful device
which can be used to avoid clipping by those versed in the art.
Also to generate clipping where this is a desired effect. It is sometimes called a
Gain Control. Both positive& negative gain is possible.
writing the equation inside max6 I had several clipping problems with the
decoding of a Soundfield ST450 signal, that has four matched line under single
knob.
The ST450 uses such a hardware implementation I designed circa 1980 for the Mk4
Soundfield. Experiment to find the best settings for you.
It is possible to have several instances (both hardware& software) of these
devices to optimise the dynamic range and clipping performance of a complex signal
processing chain at various points.
I record the b-format in a single quadro file.
If you do all recording and processing in 64b Floating Point, you may be able
to avoid infringing Microsoft patents on the Volume Control.
Message: 5
Date: Fri, 16 Mar 2012 21:53:15 +0000
From: Fons Adriaensen<f...@linuxaudio.org>
Subject: Re: [Sursound] question about simple equation
To: sursound@music.vt.edu
Message-ID:<20120316215315.ga23...@linuxaudio.org>
Content-Type: text/plain; charset=us-ascii
On Sat, Mar 17, 2012 at 05:24:39AM -0000, Richard Lee wrote:
This is an instance of a patented Microsoft software invention called a Volume
Control. There are also ancient hardware implementations of this useful device
which can be used to avoid clipping by those versed in the art.
Also to generate clipping where this is a desired effect. It is sometimes called a
Gain Control. Both positive& negative gain is possible.
Richard, you're being cruel...
Ciao,
--
FA
Vor uns liegt ein weites Tal, die Sonne scheint - ein Glitzerstrahl.
------------------------------
_______________________________________________
Sursound mailing list
Sursound@music.vt.edu
https://mail.music.vt.edu/mailman/listinfo/sursound
End of Sursound Digest, Vol 44, Issue 13
****************************************
