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Saturday, February 07, 2009
dbA
My uncle has a sound level meter, and I'm borrowing it because this has fascinated me for quite awhile, going back to high school physics class. What makes this particularly exciting isn't the running around measuring my home, although there was plenty of that:
  • Turns out that computer is as loud as I thought -- from 48 db to 57 in the living room
  • The quietest spot in the house I could find was a pretty-darn-quiet 28 db.
The main reason it's exciting is because I can now quite scientifically evaluate the effects of putting the Durabak floor liner into my car, compared to bare floor. I'll test it again when I put the Dynamat on, and once again when the window rubber is replaced.

I also got a chance to put the new engine to pace. Turns out it is, in fact, the fastest motor I've had yet. It goes from 0-60 in about ten seconds and peaks at between 80-85 miles per hour. Not bad, and enough for freeway driving, which is what I wanted.

My results from today's tests (results in parenthesis are with the windows rolled down):

Car off, fuel pump only: 50db (50db)
Starting: 95 (95db)
Idle: 82 (83.5)
Running: 90-94 (95-101)
Accelerating: 100-104 (102-107)
@ 80 MPH: 103 (104)
Peak dbA levels: 104 (110)

For a list of examples of db levels, check out my previous post. My car is about as loud as an alarm clock at idle, and as loud as a chainsaw when accelerating. OSHA would not permit a business to have employees drive my car for more than an hour of highway driving. The goal, then, should be to get my car's noise levels down to about 90 db (which I think is possible).

By comparison, the Prius (which is an extraordinarily quiet car) has the following noise levels in the same conditions:

Car off: 31
Starting: 56
Idle: 54
Running: 65
Accelerating: 73
Stereo at 2: 62
Stereo at 4: 72
Stereo at 6: 80
Stereo at 8: 87
Stereo at 10: 92.5
A/C blower on LO: 46
A/C blower on MED: 61
A/C blower on HI: 71

To be continued ...

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posted by Steve @ 9:50 PM   0 comments
Sunday, March 19, 2006
Random Thought no. 19: Remembering Physics
If there is any one person that inspired me to be a better teacher - even if I didn't know I was going to be one - it was Mr. Heim, from when I went to Brophy, my old high school.

For some reason, I remember his book (he wrote it) on physics and how it was amusing that he put a list of examples of Decibel levels. I will put it here for your and my amusement - sounds you can barely hear to sounds you'll hear just once...

15 dB - Lower limit of hearing
30 dB - Quiet library, whispers
40 dB - Living room, refrigerator
50 dB - Normal conversation
60 dB - Sewing machine, A/C unit
70 dB - Vacuum cleaner, hair dryer
80 dB - Alarm clock, garbage disposal
90 dB - Subway, lawn mower
100 dB - Chainsaw, pneumatic drill
120 dB - Rock band at the speakers
130 dB - Pain threshold
140 dB - Gunshot, jet plane
160 dB - Instant deafness
180 dB - Rocket launching pad
190 dB - Violent rupture of the eardrums

I... sometimes grin at the last one. I am probably disturbed, but it amuses me to no end. The idea that Spinal Tap really could've found the '11' that actually made their audiences' head explode.

Currently listening :
Witching Hour
By Ladytron

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posted by Steve @ 10:05 PM   0 comments
 
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Name: Steve
Home: Tucson, Arizona, United States
About Me: I like to think about things, and I occasionally like to write what I think.
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