Category Archives: Media

$99 smartboard and Chief’s interactive mount

After Johnny Lee (Carnegie Mellon Grad) came up with his $99 Wiimote-based interactive surface, several industry solutions propped up as well. The latest one is from Chief (we use their projector mounts): combined short throw mount and mac/pc compatible interactive bundle that can turn any board into a smart board:
http://www.proavmagazine.com/mounts/chief-ships-interactive-mount-bundle.aspx?rssLink=042711-Chief+Ships+Interactive+Mount+Bundle

Microphone Feedback

Aside from the cell phone-caused speaker interference, there are additional sources of noise/interference in an audio system, including mic feedback. Here are some more resources that describe ways to reduce feedback:
http://toonz.ca/bose/wiki/index.php?title=Microphone_Feedback
http://www.google.com/search?q=mic+feedback
http://en.wikipedia.org/wiki/Audio_feedback#Directivity
http://www.mediacollege.com/audio/howto/feedback.html
http://www.audiocourses.com/article113.html
http://proavmagazine.com/acoustics/designing-a-mix-minus-distributed-sound-system.aspx
http://en.wikipedia.org/wiki/Microphone#Microphone_polar_patterns
http://www.ccisolutions.com/worshiptools/learn-about-microphone-feedback

http://www.shure.com/idc/groups/public/documents/webcontent/us_pro_mics_for_music_sound_ea.pdf
http://www.shurenotes.com/issue23/article.html
http://www.shurenotes.com/issue27/article.html

http://www.dt4u.com/dtsystems/feedback.php
http://boards.straightdope.com/sdmb/archive/index.php/t-34057.html
http://www.behringer.com/EN/Products/FBQ2496.aspx
http://www.mp3backingtrax.com/article56.htm

Shielding Audio Equipment from Cell Phone Interference

In the words of Gary Guinn (AKG Acoustics), “The past two years have brought a whirlwind of engineering nightmares with Blackberry and other wireless units creating problems in wired and wireless microphones.” http://www.crownaudio.com/kb/entry/163/

Indeed, combining shielded and unshielded wires with wireless phones and other wireless devices can lead to interference and buzz (you can hear samples of the issue http://www.youtube.com/watch?v=sZEMoH2xRfM&t=0m13s, http://www.youtube.com/watch?v=emxPVUM3y54 and http://www.youtube.com/watch?v=HzufTbKiJzw

Solutions have been presented but none are ideal:

Another interesting solution (suggested here):
http://www.neutrik.com/content/products/level03.aspx?id=204_1603252336&catId=CatMSDE_audio
IEEE suggestion (add ferrite cores):
http://www.hottconsultants.com/pdf_files/aes-2007.pdf

Battle of the PDF Tools

This weekend my wife showed me the benefits of using PrimoPDF instead of PDF Creator. While PDF Creator is Open Source, PrimoPDF is commercial but still free. PrimoPDF offers easier controls for the quality of the produced PDF. Both of them, however, tend to leave off bits of complex graphs produced with MS Office. Still, if PrimoPDF’s license allows, it may be a good idea to replace PDF Creator with Primo.

http://www.primopdf.com/
http://sourceforge.net/projects/pdfcreator/