Saturday, August 27, 2011
I got so DAMN bored (actually should be stressed cos uni life is - .-) so I actually went back the "archive" below and found this post which is 3 years ago, when we just took over.
Oh and coming from an old man (Melvin Tan De Zheng), is there any JTS???
*Quote from the archive*
For those of you that are bored with studying for your exams, here's 2 applications that you can play around with:
http://phet.colorado.edu/simulations/sims.php?sim=Sound
http://phet.colorado.edu/simulations/sims.php?sim=Wave_Interference
Basically, the applications are about sound waves (duhzzz.. this is a PA blog rite?) or waves in general. Anyway, with this applications, you can better understand why putting subwoofers apart is a bad idea.
1. Simulate putting subwoofers apart by choosing the "two speakers" option, and set the frequency to very low.
2. Click on the "Add detector" button (for the 2nd application) or the "listener" button (for the 1st application).
3. By moving the detector/listener around, you will notice large areas of "dead spots" aka destructive interference. This will be shown on the detector when the amplitude of the curve reduces significantly, or when you can't hear anything much.
4. Second observation is that there is a v-shaped area in between the 2 speakers that are noticeably louder than the rest of the area. This is termed as "power alley" and will cause uneven sounding bass.
5. By shifting the frequency upwards, the above observations can still be seen/heard but they are not very obvious. Hence for full-range speakers which produce higher frequency sounds, they are spaced apart for wider coverage (at the expense of the destructive interference).
I know most of you won't bother clicking the link (except Zp maybe.. haha). Just to clarify, I'm not a no-lifer that goes on the Internet to search for such stuff (unlike some others =x), just happen that I'm taking a "sound in our daily life" elective so I might as well enrich your lives too. =D
Oh wells.... back to the books.....
pa oiii! (: 9:48 PM; (dated 28 August 2009)
posted by sam_x (:
ALL HAIL THE GREAT SAMU!!!
pa oiii! (: 8:54 PM;
posted by Mokha (:
