Could it pick up the engine noise around open headers?hehe:gears:

 

So since I've got the M6 and my RPM's are at approx 1900 at 80 we should be fine. My Z3 at 60 is at about 2500 and I get a ticket? Seems like to many variables to simply go off of engine rpm. Maybe thats why their just testing it I need the 40 MPH whistle please

 

It's not basing speed off engine RPM. It's calculating speed by calculating the speed at which the sound is moving away from the microphone. So it doesn't matter what exhaust you have and what RPM your engine is spining at.

 

It's measuring the doppler effect of the sound of your engine, not the rpms. The noise your engine makes will sound higher pitched as you come approach the sensor, and lower pitched as you move away. This shift can be measured and correlated with the vehicle's speed.

http://www.answers.com/main/ntquery?s=doppler+effect&gwp=13

 

wonder how well that microphone would hold up to the weather around certain parts of the country. For example. Wisconsin. Lots of snow, salt on the road!

 

notice that technology is being tested by a university, takes a lot more to actually get it passed and ready for use. Maybe by 2010 we might have to worry about it!

 

I'm sure you could shoot some sound toward it and jam it up!

 

throw it a rev as you're going past lol

This would actually be a case for having a ultra-quiet exhaust - or an electric car - of course then you wouldn't be speeding in the first place lol

 

throw it a rev as you're going past lol

This would actually be a case for having a ultra-quiet exhaust - or an electric car - of course then you wouldn't be speeding in the first place lol

we just finished a guy w/ a project on an electric saturn that hit 130, lol

 

I knew big brother was watching, but now he'll be listening too.

 

This does seem like it could pose a problem, but how do you distinguish which car was speeding? If you have more than one lane in each direction what happens if two cars pass at close to the same time? I bet real world testing will hurt progress on this tech. Which could be good for us.

 

bottom line....

if something can be built...then something can be built to defend it.

 

http://www.newscientisttech.com/channel/tech/mg19025485.600.html

Very interesting technology if it really works, I might have to install a whistle tip to throw it off.

the whistles do in fact go "wooo wooo"

 

That won't last. People will get out of their cars and destroy them. I know i would.

 

As with all devices that measure anything....there is away to defeat it

 

My preplanned defense: "Your honor, I simply shifted from 3rd to 6th as I passed the speed trap and the change in the engine and exhaust pitch apparently caused the device to mistakenly calculate that I was doing 145 mph."

"Case dismissed..."

 

My preplanned defense: "Your honor, I simply shifted from 3rd to 6th as I passed the speed trap and the change in the engine and exhaust pitch apparently caused the device to mistakenly calculate that I was doing 145 mph."

"Case dismissed..."

My thoughts exactly!! :judge:

Plus...what affect will echoing (highway barriers, tractor trailers), winds (air pressure before your car is higher than the hole left behind it), temperatures, and humidity (incl. rain or snow) have? All of these impact the true speed of sound!

:stickpoke

 

oh yeah...but we're forgetting the most important variable...a witness and testimony. Without a witness to state under oath that A) the equipment was properly calibrated B) properly positioned C) the vehicle and road/weather conditions can be verified at that point in time D) the traffic conditions didn't impact anything and E) the vehicle didn't shift gears, or the coolant fan came on/off, etc...all you have is a picture and mumbo jumbo calculations based unverfied factors....I give you your reasonable doubt.

 

Problems with the Sound Measurement System

Some interesting comments from another board about this topic:

Doppler Effect: Apparent frequency change of waves which results when the source and recipient of the waves move toward, and then away, from each other. A shift in frequency caused by satellite movement toward or away from your location. When the satellite is coming toward you, the Doppler shift decreases the frequency. When the satellite is going away from you, the frequency increases. Like the waves from the ocean piling up in front of a storm.

So if you are increasing or decreasing your speed, the SOURCE SOUND changes. This will cause an error in the measuring unit. The unit is dependant on a CONSTANT SOUND FREQUENCY to accurately analyze changes. Again, easy to beat in court.

Add to that, they State would need a sound expert to explain HOW the unit filters, what filters are used, how they can easily be fallible, etc. Trust me, i could easily go on and on. Bring one to court, i could fool it as many times as you desire with a simply test.

Case dismissed

-- and --

So if you are increasing or decreasing your speed, the SOURCE SOUND changes. This will cause an error in the measuring unit. The unit is dependant on a CONSTANT SOUND FREQUENCY to accurately analyze changes. Again, easy to beat in court.

Add to that, they State would need a sound expert to explain HOW the unit filters, what filters are used, how they can easily be fallible, etc. Trust me, i could easily go on and on. Bring one to court, i could fool it as many times as you desire with a simply test.

Case dismissed

I think a another big problem, at least for now, would be to identify the sound profile of any particular car on busy freeways.

But what really gets me PO'd is that I worked at Battelle (developer of the sound speed detector) in the Northwest while I was a grad student. Battelle prided itself on being a "think tank" having developed the following: (1) the Xerox process; (2) the candy coating on M&Ms; and (3) the process for making copper clad quarters and dimes.

In reality, Battelle was, in my opinion, completely addicted to government funding -- it fed like a hog off of government funds and your tax dollars. Thank's a lot Battelle.......

This second quote mentions one of the problems: identifying the car in question. You'd have to have some sort of roadside camera setup to photograph the license plate, and there are license plate photo defeat systems available if this technology began to be used in a significant way. Cf:

http://www.specterguard.com/index.html

and

http://www.phantomplate.com/

 

I'll just set up some good speakers in the engine bay and blast a continous loop of a Prius engine.

 

I'll just set up some good speakers in the engine bay and blast a continous loop of a Prius engine.

http://www.vroombox.com/

Padre

 

Passive detection is the future...the same could be done with cameras and image processing.

 

http://www.vroombox.com/

Padre

That is the filet minion of rice. This time flattery is not a compliment.

 

Well I have no catback so I guess at no matter what speed I would be caught doing lets say 130-180mph.... since the car sounds loud as hell no matter what. haha I always wake up my friends parents as I leave their house, and I get the attention of everyone on the street.

 

That vroom box has to be the most ridiculous thing I have ever seen! I bet they sell thousands of them