Thursday, August 28, 2008
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;
posted by sam_x (:
Sunday, August 24, 2008
Hmmm, thought that the blog shouldn't be having some academic stuff on the very first page, so updating for... fun...
2 days ago was our CCO BIRTHDAY!!!
No big deal, but SAMU CAME BACK!!!
Abit big deal, but Prelim almost over!!!
Isit? Anyway good luck to all Seniors for their prelims and As, Juniors (esp. myself) for our promos, and and and, ya, 加油！！！
Lets do this for our small and cosy family.
pa oiii! (: 11:14 PM;
posted by Mokha (:
Thursday, August 14, 2008
It's been some time...
Just wanted to let you all take a look while you happily mug your way to your AAAA batteries. There's a lot in stock just waiting for you to purchase yup (=
Now you know why we are failing chemistry ehh?
That's why studying PA is better, all the facts are all laid out for you to learn. Got this nice book from the library that taught me some new stuff (= Interested?
Nvm (=
pa oiii! (: 12:31 AM;
posted by Discmon (:
Sunday, August 10, 2008
Today at Sentosa Tanjung Beacht:
People who
got dunked:
Jeffrey (forcefully)
Zi Quan (forcefully)
Melvin (forcefully)
Ka Tsun (forcefully)
Samuel (self-sacrificed)
Yi Neng (voluntarily)
Person who tried to dunk but failed miserably:
Ka Tsun
People who
didn't get dunked:
HONG HSIANG WEIMelissa
Cass
Ting Yun
Ling Ling
Hazel
Eugenie
At Habourfront Subway:
People who ate the
Foot-long sandwich:
Jeffrey
Zi Quan
Ka Tsun
Samuel
Yi Neng
People who ate the
6-inch sandwich:
HONG HSIANG WEIMelissa
Cass
Ting Yun
Ling Ling
Hazel
Eugenie
*Edited out*
pa oiii! (: 6:07 PM;
posted by sam_x (:
Tuesday, August 05, 2008
| PA Crew 07.08 | 07S0506 | 07S0703 | 07S1113 | 07S14 | 07S1417 | 07S1616 | 07S1617 | 07S1822 | 07S21 | 07S2316 | 07S2323 | 05IP0422 |
|
|
|
|
|
|
|
|
|
| Levon | Yu Xuan | Zhi Ping | Huzaifah | Eng Yian | Yan Ling | Wang Lu | Si Yuan | Biondi | Nicholas | Kai Zhong | Tuonan |
|
|
|
|
|
|
|
|
|
| Subtotal (2007) | 5.5 | 146.5 | 153.5 | 58.5 | 56.5 | 56 | 17 | 76 | - | 45 | 50.5 | 9 |
|
|
|
|
|
|
|
|
|
| Subtotal (June 2008) | 29 | 87 | 214 | 12 | 119 | 155.5 | 0 | 153.5 | 12.5 | 89.5 | 139 | 24.5 |
|
|
|
|
|
|
|
|
|
| Total | 34.5 | 233.5 | 367.5 | 70.5 | 175.5 | 211.5 | 17 | 229.5 | 12.5 | 134.5 | 189.5 | 33.5 |
|
|
|
|
|
|
|
|
|
|
| PA Crew 07IP | 07IP0212 | 07IP02 | 07IP0217 | 07IP0218 | 07IP0524 | 07IP0622 | 07IP0623 |
|
|
|
|
|
|
|
|
|
|
|
|
|
|
| Grace | Jae Sung | Mervyn | Hsiang Wei | Yijing | Jingwen | Shijin |
|
|
|
|
|
|
|
|
|
|
|
|
|
|
| Subtotal (2007) | 45 | 0 | 62.5 | 32 | 48 | 64 | 64 |
|
|
|
|
|
|
|
|
|
|
|
|
|
|
| Subtotal (June 2008) | 33.5 |
| 133 | 99.5 | 48 | 93 | 88 |
|
|
|
|
|
|
|
|
|
|
|
|
|
|
| Subtotal (2009) |
| - |
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
| Subtotal (2010) |
| - |
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
| Total | 78.5 | 0 | 195.5 | 131.5 | 96 | 157 | 152 |
|
|
|
|
|
|
|
|
|
|
|
|
|
|
pa oiii! (: 4:06 PM;
posted by KzTay (:
Sunday, August 03, 2008
Just a quick post: (I might post something else on my thoughts, but its not exactly a good time to do it now)Attention all! The events + Cip hours for all of the PA stuff has just been added!!! (.... sure took long enough)Please do go and update ASAP (=Also, please note that the cip hours for PA is NOT under the PA&AVA group heading, but is under CIP/School heading. So if you can't find it, its there.Good luck (=p.s. remember to round up your CIP hours!
pa oiii! (: 12:46 PM;
posted by Discmon (:
Saturday, August 02, 2008
Just wanna say...
Well done for Rock Nite!!!We totally rocked the house down!! Great job everyone, hope you guys learnt alot from this event.
Now for the more emo part...
I really enjoyed the past 8 months I spent with you guys.. every single one of you made my experience so memorable. I'm sure all of us have gained something in the company of each other =)
NJPA rocks!
Oh yah.. one last thing. I managed to salvage this picture from the school laptop before returning it.
pa oiii! (: 1:15 AM;
posted by sam_x (:
Now you know why we are failing chemistry ehh?