![Page 1: Using Pressure and Gradient to Derive Microphone Patterns Audio Days 2011 Paris David Josephson Josephson Engineering, Inc. Santa Cruz, California](https://reader031.vdocuments.us/reader031/viewer/2022020217/55162626550346c6758b4944/html5/thumbnails/1.jpg)
Using Pressure and Gradient to Derive Microphone Patterns
Audio Days 2011
Paris
David Josephson
Josephson Engineering, Inc.
Santa Cruz, California
![Page 2: Using Pressure and Gradient to Derive Microphone Patterns Audio Days 2011 Paris David Josephson Josephson Engineering, Inc. Santa Cruz, California](https://reader031.vdocuments.us/reader031/viewer/2022020217/55162626550346c6758b4944/html5/thumbnails/2.jpg)
Scalars and Vectors
• nondirectional/pressure/scalar– responds to pressure from any direction
• directional/pressure-gradient/vector– responds to difference in pressure between
two points
![Page 3: Using Pressure and Gradient to Derive Microphone Patterns Audio Days 2011 Paris David Josephson Josephson Engineering, Inc. Santa Cruz, California](https://reader031.vdocuments.us/reader031/viewer/2022020217/55162626550346c6758b4944/html5/thumbnails/3.jpg)
Pressure Response
![Page 4: Using Pressure and Gradient to Derive Microphone Patterns Audio Days 2011 Paris David Josephson Josephson Engineering, Inc. Santa Cruz, California](https://reader031.vdocuments.us/reader031/viewer/2022020217/55162626550346c6758b4944/html5/thumbnails/4.jpg)
Pressure Response
![Page 5: Using Pressure and Gradient to Derive Microphone Patterns Audio Days 2011 Paris David Josephson Josephson Engineering, Inc. Santa Cruz, California](https://reader031.vdocuments.us/reader031/viewer/2022020217/55162626550346c6758b4944/html5/thumbnails/5.jpg)
Pressure Gradient Response
![Page 6: Using Pressure and Gradient to Derive Microphone Patterns Audio Days 2011 Paris David Josephson Josephson Engineering, Inc. Santa Cruz, California](https://reader031.vdocuments.us/reader031/viewer/2022020217/55162626550346c6758b4944/html5/thumbnails/6.jpg)
Pressure Gradient Response
![Page 7: Using Pressure and Gradient to Derive Microphone Patterns Audio Days 2011 Paris David Josephson Josephson Engineering, Inc. Santa Cruz, California](https://reader031.vdocuments.us/reader031/viewer/2022020217/55162626550346c6758b4944/html5/thumbnails/7.jpg)
![Page 8: Using Pressure and Gradient to Derive Microphone Patterns Audio Days 2011 Paris David Josephson Josephson Engineering, Inc. Santa Cruz, California](https://reader031.vdocuments.us/reader031/viewer/2022020217/55162626550346c6758b4944/html5/thumbnails/8.jpg)
Cardioid pattern
+ =
![Page 9: Using Pressure and Gradient to Derive Microphone Patterns Audio Days 2011 Paris David Josephson Josephson Engineering, Inc. Santa Cruz, California](https://reader031.vdocuments.us/reader031/viewer/2022020217/55162626550346c6758b4944/html5/thumbnails/9.jpg)
![Page 10: Using Pressure and Gradient to Derive Microphone Patterns Audio Days 2011 Paris David Josephson Josephson Engineering, Inc. Santa Cruz, California](https://reader031.vdocuments.us/reader031/viewer/2022020217/55162626550346c6758b4944/html5/thumbnails/10.jpg)
![Page 11: Using Pressure and Gradient to Derive Microphone Patterns Audio Days 2011 Paris David Josephson Josephson Engineering, Inc. Santa Cruz, California](https://reader031.vdocuments.us/reader031/viewer/2022020217/55162626550346c6758b4944/html5/thumbnails/11.jpg)
What is B-Format?
• signal format for Ambisonics
• W – omnidirectional (pressure)
• X – figure-8 (cos ) facing front-to-back
• Y – figure 8 facing side-to-side
• Z – figure 8 facing up-to-down
![Page 12: Using Pressure and Gradient to Derive Microphone Patterns Audio Days 2011 Paris David Josephson Josephson Engineering, Inc. Santa Cruz, California](https://reader031.vdocuments.us/reader031/viewer/2022020217/55162626550346c6758b4944/html5/thumbnails/12.jpg)
Native B-format
• omnidirectional mic produces W signal
• front-facing bidirectional mic produces X
• side-facing bidirectional mic produces Y
• (optional) up-down mic for Z
![Page 13: Using Pressure and Gradient to Derive Microphone Patterns Audio Days 2011 Paris David Josephson Josephson Engineering, Inc. Santa Cruz, California](https://reader031.vdocuments.us/reader031/viewer/2022020217/55162626550346c6758b4944/html5/thumbnails/13.jpg)
Set pattern with ratio of W to X
a + b cos()
a ... is how much of the omni (W)
b ... is how much of the fig-8 (X)
![Page 14: Using Pressure and Gradient to Derive Microphone Patterns Audio Days 2011 Paris David Josephson Josephson Engineering, Inc. Santa Cruz, California](https://reader031.vdocuments.us/reader031/viewer/2022020217/55162626550346c6758b4944/html5/thumbnails/14.jpg)
+ =
X + Y = another figure-8 ...pointed at an angle corresponding to the ratio of X and Y
![Page 15: Using Pressure and Gradient to Derive Microphone Patterns Audio Days 2011 Paris David Josephson Josephson Engineering, Inc. Santa Cruz, California](https://reader031.vdocuments.us/reader031/viewer/2022020217/55162626550346c6758b4944/html5/thumbnails/15.jpg)
5.1 from B-format
• FC = aW + bX (where a/b sets pattern)
• FL = aW + bX + cY
• FR = aW + bX - cY
• SL = aW - bX + cY
• SR = aW - bX - cY
• LFE = low passed W
![Page 16: Using Pressure and Gradient to Derive Microphone Patterns Audio Days 2011 Paris David Josephson Josephson Engineering, Inc. Santa Cruz, California](https://reader031.vdocuments.us/reader031/viewer/2022020217/55162626550346c6758b4944/html5/thumbnails/16.jpg)
Josephson C-700S
![Page 17: Using Pressure and Gradient to Derive Microphone Patterns Audio Days 2011 Paris David Josephson Josephson Engineering, Inc. Santa Cruz, California](https://reader031.vdocuments.us/reader031/viewer/2022020217/55162626550346c6758b4944/html5/thumbnails/17.jpg)
W
X
Y
![Page 18: Using Pressure and Gradient to Derive Microphone Patterns Audio Days 2011 Paris David Josephson Josephson Engineering, Inc. Santa Cruz, California](https://reader031.vdocuments.us/reader031/viewer/2022020217/55162626550346c6758b4944/html5/thumbnails/18.jpg)
Billy Pitrone – guitar and vocal Sarah Eblin – bass and vocal Pete Hicks – fiddle, mandolin and vocalRob Horgan – banjo
Recorded by Dave Nielsen at Rancho Armadillo, Santa Cruz
www.beancreekbluegrass.com
![Page 19: Using Pressure and Gradient to Derive Microphone Patterns Audio Days 2011 Paris David Josephson Josephson Engineering, Inc. Santa Cruz, California](https://reader031.vdocuments.us/reader031/viewer/2022020217/55162626550346c6758b4944/html5/thumbnails/19.jpg)
Anna Clyne, rewind
Cabrillo Music Festival Orchestra, Marin Alsop, director Recorded by Cuco Daglio www.cabrillomusic.org
![Page 20: Using Pressure and Gradient to Derive Microphone Patterns Audio Days 2011 Paris David Josephson Josephson Engineering, Inc. Santa Cruz, California](https://reader031.vdocuments.us/reader031/viewer/2022020217/55162626550346c6758b4944/html5/thumbnails/20.jpg)