Pipe Mods and Riding Area Closures
#21
Originally posted by: WhoDatInDaMud
You are not alone. Minnesota now prohibits any modification to mufflers. I think I know where that is -
Found it. http://files.dnr.state.mn.us/rlp/reg...vregs05_06.pdf
Mufflers
• Mufflers must have a federally approved spark arrestor.
• Overall noise emission may not exceed 99 decibels at a distance
of 20 inches.
• Mufflers may not be altered to increase motor noise, or have a
cutout, bypass, or similar device except for organized events.
You are not alone. Minnesota now prohibits any modification to mufflers. I think I know where that is -
Found it. http://files.dnr.state.mn.us/rlp/reg...vregs05_06.pdf
Mufflers
• Mufflers must have a federally approved spark arrestor.
• Overall noise emission may not exceed 99 decibels at a distance
of 20 inches.
• Mufflers may not be altered to increase motor noise, or have a
cutout, bypass, or similar device except for organized events.
#22
You guys realize the the difference between 95db and 99db don't you? 99db is better than twice as loud as 95db. Each increase of 3 db doubles the volume of the sound.
99= more than 2x95? No.
Two ATV's both emitting 95dB will produce 98dB. If you add a second equal source of sound, the dB will rise by 3. A single dB is basically the smallest change in volume a human can detect. 99dB is noticeably louder than 95, but nowhere NEAR twice as loud.
#23
Originally posted by: Chumley
99= more than 2x95? No.
Two ATV's both emitting 95dB will produce 98dB. If you add a second equal source of sound, the dB will rise by 3. A single dB is basically the smallest change in volume a human can detect. 99dB is noticeably louder than 95, but nowhere NEAR twice as loud.
You guys realize the the difference between 95db and 99db don't you? 99db is better than twice as loud as 95db. Each increase of 3 db doubles the volume of the sound.
99= more than 2x95? No.
Two ATV's both emitting 95dB will produce 98dB. If you add a second equal source of sound, the dB will rise by 3. A single dB is basically the smallest change in volume a human can detect. 99dB is noticeably louder than 95, but nowhere NEAR twice as loud.
I work in communications and in avionics in the past and yes, in the db scale; 98db is double 95db. You better do some research because it is a fact, he!! just look up the definition in the dictionary. And "A single dB is basically the smallest change in volume a human can detect." is not only wrong but you have some reading to do. Most people talk in the 45db to 55 db range.
#24
News flash Bear- You don't know everything. Save your years of experience speech, I've read it numerous times. It won't save you here.
A chainsaw is rated around 115-120 @3ft. If its 120, that means its 24dB more than my 96dB atv. By your logic, every 3dB is doubled, that means over the difference of 24 it has doubled 8 times. Do the math, is that chainsaw 256 (2^8) times louder than my atv? Hell no it's not.
However, if you double the source power (watts), there is a 3dB increase. I'm reallly thinking that is where you are confused. Doubling the source power does NOT double the decibel output.
Looks like you have some reading to do.
A chainsaw is rated around 115-120 @3ft. If its 120, that means its 24dB more than my 96dB atv. By your logic, every 3dB is doubled, that means over the difference of 24 it has doubled 8 times. Do the math, is that chainsaw 256 (2^8) times louder than my atv? Hell no it's not.
However, if you double the source power (watts), there is a 3dB increase. I'm reallly thinking that is where you are confused. Doubling the source power does NOT double the decibel output.
Looks like you have some reading to do.
#26
I don't agree with you WideOpen -
This thread is about Noise and how it is closing riding areas.
There is a debate on how noise is measured.
Why is it that it is no longer tolerable for people to disagree?
Intolerence for anything the least bit uncomfortable is turning our whole country into a bunch of sissy whiners.
Sometimes great infomation comes from great debate.
Buck up a little as men sharpen their iron in battle. It can be a learning expereince.
But as always, let's be respectful - in battle and all other things.
Stick to the code....
This thread is about Noise and how it is closing riding areas.
There is a debate on how noise is measured.
Why is it that it is no longer tolerable for people to disagree?
Intolerence for anything the least bit uncomfortable is turning our whole country into a bunch of sissy whiners.
Sometimes great infomation comes from great debate.
Buck up a little as men sharpen their iron in battle. It can be a learning expereince.
But as always, let's be respectful - in battle and all other things.
Stick to the code....
#27
Originally posted by: Chumley
News flash Bear- You don't know everything. Save your years of experience speech, I've read it numerous times. It won't save you here.
A chainsaw is rated around 115-120 @3ft. If its 120, that means its 24dB more than my 96dB atv. By your logic, every 3dB is doubled, that means over the difference of 24 it has doubled 8 times. Do the math, is that chainsaw 256 (2^8) times louder than my atv? Hell no it's not.
However, if you double the source power (watts), there is a 3dB increase. I'm reallly thinking that is where you are confused. Doubling the source power does NOT double the decibel output.
Looks like you have some reading to do.
News flash Bear- You don't know everything. Save your years of experience speech, I've read it numerous times. It won't save you here.
A chainsaw is rated around 115-120 @3ft. If its 120, that means its 24dB more than my 96dB atv. By your logic, every 3dB is doubled, that means over the difference of 24 it has doubled 8 times. Do the math, is that chainsaw 256 (2^8) times louder than my atv? Hell no it's not.
However, if you double the source power (watts), there is a 3dB increase. I'm reallly thinking that is where you are confused. Doubling the source power does NOT double the decibel output.
Looks like you have some reading to do.
http://www.jimprice.com/prosound/db.htm
#28
If something doubles 8 times, thats the same as 256 times the first sound. Volume doubles approx every 10 dB, not 3. That's a mighty big difference.
Again, 99dB has double the POWER, but not double the volume.
Seriously, get over yourself.
Taken from: http://arts.ucsc.edu/EMS/Music/tech_.../teces_06.html
Taken from: http://hyperphysics.phy-astr.gsu.edu.../sound/db.html
Again, 99dB has double the POWER, but not double the volume.
Seriously, get over yourself.
The usefulness of all this becomes becomes apparent when we think about how the ear perceives loudness. First of all, the ear is very sensitive. The softest audible sound has a power of about 0.000000000001 watt/sq. meter and the threshold of pain is around 1 watt/sq. meter, giving a total range of 120dB. In the second place, our judgment of relative levels of loudness is somewhat logarithmic. If a sound has 10 times the power of a reference (10dB) we hear it as twice as loud. If we merely double the power (3dB), the difference will be just noticeable.
The factor of 10 multiplying the logarithm makes it decibels instead of Bels, and is included because about 1 decibel is the just noticeable difference (JND) in sound intensity for the normal human ear........Another consideration which prompts the use of powers of 10 for sound measurement is the rule of thumb for loudness: it takes about 10 times the intensity to sound twice as loud.
#29
Originally posted by: Chumley
If something doubles 8 times, thats the same as 256 times the first sound. Volume doubles approx every 10 dB, not 3. That's a mighty big difference.
Again, 99dB has double the POWER, but not double the volume.
Seriously, get over yourself.
Taken from: <a target=new class=ftalternatingbarlinklarge href="http://
http://arts.ucsc.edu/EMS/Music/tech_background/TE-06/teces_06.html">http://arts.ucsc.edu/EMS/Music/tech_background/TE-06/teces_06.html</a>
Taken from: http://hyperphysics.phy-astr.gsu.edu.../sound/db.html
If something doubles 8 times, thats the same as 256 times the first sound. Volume doubles approx every 10 dB, not 3. That's a mighty big difference.
Again, 99dB has double the POWER, but not double the volume.
Seriously, get over yourself.
The usefulness of all this becomes becomes apparent when we think about how the ear perceives loudness. First of all, the ear is very sensitive. The softest audible sound has a power of about 0.000000000001 watt/sq. meter and the threshold of pain is around 1 watt/sq. meter, giving a total range of 120dB. In the second place, our judgment of relative levels of loudness is somewhat logarithmic. If a sound has 10 times the power of a reference (10dB) we hear it as twice as loud. If we merely double the power (3dB), the difference will be just noticeable.
http://arts.ucsc.edu/EMS/Music/tech_background/TE-06/teces_06.html">http://arts.ucsc.edu/EMS/Music/tech_background/TE-06/teces_06.html</a>
The factor of 10 multiplying the logarithm makes it decibels instead of Bels, and is included because about 1 decibel is the just noticeable difference (JND) in sound intensity for the normal human ear........Another consideration which prompts the use of powers of 10 for sound measurement is the rule of thumb for loudness: it takes about 10 times the intensity to sound twice as loud.
You are talking db in the electronic spectrum, not the db of noise thay our ears hear. That are not the same db. Yours is dbm which reflects speaker output power. Not db spl for noise measusing.
Sound Pressure Level
The definition of dB SPL is the 20 log of the ratio between the measured sound pressure level and the reference point. This reference point is defined as 0.000002 Newtons per square meter, the threshold of hearing. However, the threshold of hearing (and sensitivity to level) changes by frequency and for soft and loud sounds, as discovered by Fletcher and Munson in 1933, shown in the graph below:
Note that human hearing is relatively insensitive to low bass (below 100 Hz), and also compresses at higher sound levels.
Here are some typical sounds, and their levels.
Sounds dB SPL
Rocket Launching 180
Jet Engine 140
Thunderclap, Air Raid Siren 1 Meter 130
Jet takeoff (200 ft) 120
Rock Concert, Discotheque 110
Firecrackers, Subway Train 100
Heavy Truck (15 Meter), City Traffic 90
Alarm Clock (1 Meter), Hair Dryer 80
Noisy Restaurant, Business Office 70
Air Conditioning Unit, Conversational Speech 60
Light Traffic (50 Meter), Average Home 50
Living Room, Quiet Office 40
Library, Soft Whisper (5 Meter) 30
Broadcasting Studio, Rustling Leaves 20
Hearing Threshold 0
You need to get your definitions of db right. Otherwise not bdm, but db spl.
#30
As I'm sure you know, a dB is not a unit of volume but a unit of change in volume. (Staying on topic of dB's in relation to this topic)
My main and only point has been that 99dB is no where near twice as loud as 96dB. It takes about 10dB increase to double volume, not 3dB. Everything else is irrelevant as far as this forum is concerned.
My main and only point has been that 99dB is no where near twice as loud as 96dB. It takes about 10dB increase to double volume, not 3dB. Everything else is irrelevant as far as this forum is concerned.


