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I know it has something to do with exhaust but is it really? What does it stand for, and how is it calculated?
What is dB?
- Thread starter Driftnewb110
- 33 comments
- 1,581 views
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Decibels:
"Decibels (abbreviated dB) are the unit of measuring the loudness (or intensity) of sounds. 0 dB is the faintest audible sound. The decibel scale is logarithmic. Blue whale calls are up to 188 dB; this is the loudest animal sound, and is painful to the human ear. Volcano eruptions are one of the loudest sounds on Earth and are over 272 dB..."
"Decibels (abbreviated dB) are the unit of measuring the loudness (or intensity) of sounds. 0 dB is the faintest audible sound. The decibel scale is logarithmic. Blue whale calls are up to 188 dB; this is the loudest animal sound, and is painful to the human ear. Volcano eruptions are one of the loudest sounds on Earth and are over 272 dB..."
- 1,264
I don't know. Listening to Spinal Tap at "11" can really melt your brain. They rip!!!EmohawkThe loudest band in the world is Manowar (130 dB), they'll kick your ass.
On a similar note, Polk Audio used to make a home theater speaker system called the SRT System (Signature Reference Theater). It was a massive system. In total, the system had over 30 drivers. It shipped with a special SPL meter you used when setting up the system. It was used to make sure the system didn't cause damage to you or your home.
If used in too small of a room, the system was capable of over 120dB, and could damage windows, glass tables, and your ears. IT WAS AWESOME!!! A high-end home theater store here in Omaha had one set up a while back. It was over $15k for the system, but holy crap was it sweet. And yes, it was frickin loud.
Hilg
- 120
The dB unit comes from the Bel unit, a decibel is 1/10th of a Bel. It was invented by the Bell telephone labs as a way of expressing the reduction in audio level over a length of phone cable. The decibel is actually a dimensionless unit, used more usually as a method of expressing a ratio between two values of electrical power in electronic circuits.
In acoustics it represents a weighted logarithmic scale of the real measure of acoustic loudness, called SPL or sound pressure level. It's logarithmic because humans detect sound at an almost logarithmic scale. Similar to the Richter scale, which can be expressed in dB, where every integer number is 10 times the previous (A force 8 is ten times more violent than a force 7). Logarithmic means that for every 3 or so dB the power of the sound doubles. However humans detect a doubling of "volume" every 10dB or so. Typically 200dB will kill you, 190 will break your eardrums and anything over 130 will do you permanent damage.
The only man made device that can go over 200 is the space shuttle at take off. These figures are only general though and will vary between people.
cheers,
Kurtis.
In acoustics it represents a weighted logarithmic scale of the real measure of acoustic loudness, called SPL or sound pressure level. It's logarithmic because humans detect sound at an almost logarithmic scale. Similar to the Richter scale, which can be expressed in dB, where every integer number is 10 times the previous (A force 8 is ten times more violent than a force 7). Logarithmic means that for every 3 or so dB the power of the sound doubles. However humans detect a doubling of "volume" every 10dB or so. Typically 200dB will kill you, 190 will break your eardrums and anything over 130 will do you permanent damage.
The only man made device that can go over 200 is the space shuttle at take off. These figures are only general though and will vary between people.
cheers,
Kurtis.
- 11,462
- U.K
- Paganisterr
- Ak Paganister
dB of every day things:
Home
50 refrigerator
50 - 60 electric toothbrush
50 - 75 washing machine
50 - 75 air conditioner
50 - 80 electric shaver
55 coffee percolator
55 - 70 dishwasher
60 sewing machine
60 - 85 vacuum cleaner
60 - 95 hair dryer
65 - 80 alarm clock
70 TV audio
70 - 80 coffee grinder
70 - 95 garbage disposal
75 - 85 flush toilet
80 pop-up toaster
80 doorbell
80 ringing telephone
80 whistling kettle
80 - 90 food mixer or processor
80 - 90 blender
80 - 95 garbage disposal
110 baby crying
110 squeaky toy held close to the ear
135 noisy squeeze toys
Work
40 quiet office, library
50 large office
65 - 95 power lawn mower
80 manual machine, tools
85 handsaw
90 tractor
90 - 115 subway
95 electric drill
100 factory machinery
100 woodworking class
105 snow blower
110 power saw
110 leafblower
120 chain saw, hammer on nail
120 pneumatic drills, heavy machine
120 jet plane (at ramp)
120 ambulance siren
125 chain saw
130 jackhammer, power drill
130 air raid
130 percussion section at symphony
140 airplane taking off
150 jet engine taking off
150 artillery fire at 500 feet
180 rocket launching from pad
Recreation
40 quiet residential area
70 freeway traffic
85 heavy traffic, noisy restaurant
90 truck, shouted conversation
95 - 110 motorcycle
100 snowmobile
100 school dance, boom box
110 disco
110 busy video arcade
110 symphony concert
110 car horn
110 -120 rock concert
112 personal cassette player on high
117 football game (stadium)
120 band concert
125 auto stereo (factory installed)
130 stock car races
143 bicycle horn
150 firecracker
156 capgun
157 balloon pop
162 fireworks (at 3 feet)
163 rifle
166 handgun
170 shotgun
Noise levels above 85 dB will harm hearing over time and noise levels above 140dB can cause damage to hearing after just one exposure.
Home
50 refrigerator
50 - 60 electric toothbrush
50 - 75 washing machine
50 - 75 air conditioner
50 - 80 electric shaver
55 coffee percolator
55 - 70 dishwasher
60 sewing machine
60 - 85 vacuum cleaner
60 - 95 hair dryer
65 - 80 alarm clock
70 TV audio
70 - 80 coffee grinder
70 - 95 garbage disposal
75 - 85 flush toilet
80 pop-up toaster
80 doorbell
80 ringing telephone
80 whistling kettle
80 - 90 food mixer or processor
80 - 90 blender
80 - 95 garbage disposal
110 baby crying
110 squeaky toy held close to the ear
135 noisy squeeze toys
Work
40 quiet office, library
50 large office
65 - 95 power lawn mower
80 manual machine, tools
85 handsaw
90 tractor
90 - 115 subway
95 electric drill
100 factory machinery
100 woodworking class
105 snow blower
110 power saw
110 leafblower
120 chain saw, hammer on nail
120 pneumatic drills, heavy machine
120 jet plane (at ramp)
120 ambulance siren
125 chain saw
130 jackhammer, power drill
130 air raid
130 percussion section at symphony
140 airplane taking off
150 jet engine taking off
150 artillery fire at 500 feet
180 rocket launching from pad
Recreation
40 quiet residential area
70 freeway traffic
85 heavy traffic, noisy restaurant
90 truck, shouted conversation
95 - 110 motorcycle
100 snowmobile
100 school dance, boom box
110 disco
110 busy video arcade
110 symphony concert
110 car horn
110 -120 rock concert
112 personal cassette player on high
117 football game (stadium)
120 band concert
125 auto stereo (factory installed)
130 stock car races
143 bicycle horn
150 firecracker
156 capgun
157 balloon pop
162 fireworks (at 3 feet)
163 rifle
166 handgun
170 shotgun
Noise levels above 85 dB will harm hearing over time and noise levels above 140dB can cause damage to hearing after just one exposure.
- 1,534
- Bazra1985
- xSHAx BaZrA
FamineLet's have some fun here...
It's possible for sounds to register in a minus number of decibels. How?
Thats why we cant hear a dog whistle, Humans cant hear below a certain dB but dogs can, but to register in minus ???? thats weird if something makes a sound im pretty sure it makes a sound - if you know wat i mean
- 120
Ref: Negative dB.
Zero dB does not mean no sounds or noise in an acoustic sense. It is the commonly taken average limit of human hearing, I've looked about and its 20 micropascals. This is a pressure and so can be expressed in psi if you want to, (100,000Pa = 14.5 psi approx) which gives 0.0000029psi. Not much then.
Negative dB is just any value less than 20mPa.
Kurtis.
Zero dB does not mean no sounds or noise in an acoustic sense. It is the commonly taken average limit of human hearing, I've looked about and its 20 micropascals. This is a pressure and so can be expressed in psi if you want to, (100,000Pa = 14.5 psi approx) which gives 0.0000029psi. Not much then.
Negative dB is just any value less than 20mPa.
Kurtis.
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WOW! So 95dB is loud huh? The CHP says that an exhuast system can be louder than 95dB.
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It is a measurement of pressure a sound puts on the ears... since that is all sound is...
- 1,264
As far as I can find, the only systems that even comes close to that # you gave is the Klipsch Pro Media Ultra system and the Logitech Z5500. Those both costs $350, and will do 115dB. But, that 115dB is at listening position, which is like 3ft from the speakers. The Polk system I was talking about could do over 120 very easilly, and in a 600 sq./ft room, not just from a couple feet away. I don't doubt your system is loud, but the loud that this Polk system can produce is almost beyond words.Ghost C
Hilg
- 630
Is there a way to calculate dBs? I want to see how many dBs my go-ped is.
nah its like absolute zero with temperature, lowest known tempurature in which EVERYTHING freezes (and crystalizes i think)FamineLet's have some fun here...
It's possible for sounds to register in a minus number of decibels. How?
so 0 in db would be the quietest known sound level
at least this is my understanding
Joey D
Premium
- 47,645
- Lakes of the North, MI
- GTP_Joey
- GTP Joey
Driftnewb110
Only calc I remember from physics. You need Intensity(I) though
dB = 10Log(base 10) {I/I(naught)}
But here is a website I found for ya since its hard to see what I'm saying.
http://230nsc1.phy-astr.gsu.edu/hbase/sound/db.html
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....BlazinXtreme
Thats very confusing lets just pretend I never asked my question.
