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Any 1 no about sound waves?
26 posts · Started by BASH69 · 18 Mar 2010
Post 2 by Twisted Jester,
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Post 3 by BASH69,
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Post 4 by Twisted Jester,
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Post 5 by bic_bicknell,
#5I laughed when I read this 'cos it's something that went through in my mind when I refitted my Akras a few weeks ago.
I ended up doing things based on aesthetics, as I always do, so I turned the outlets slightly to point inwards slightly - this is just SO the way they should be to fit with the tail design and look better from the rear of the bike. They have aesthetic KARMA this way.
As a joke I told my son that the two exhaust pules would meet together about 2 feet from the rear of the bike and give an after burn effect. This would equate to at least another 10 miles an hour - about the difference orange Superdukes lag behind the black ones - so I reckon turning those end pipes in has doubled the gap between mine and TJ's top speed.
I ended up doing things based on aesthetics, as I always do, so I turned the outlets slightly to point inwards slightly - this is just SO the way they should be to fit with the tail design and look better from the rear of the bike. They have aesthetic KARMA this way.
As a joke I told my son that the two exhaust pules would meet together about 2 feet from the rear of the bike and give an after burn effect. This would equate to at least another 10 miles an hour - about the difference orange Superdukes lag behind the black ones - so I reckon turning those end pipes in has doubled the gap between mine and TJ's top speed.
Post 6 by Plipton,
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Post 7 by BASH69,
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Post 8 by Plipton,
#8OK, I've done a bit of maths....
This is threoretical and assumes the main exhaust frequency is 500Hz.
Speed of sound is approx 330M/S
Wavelength of 500Hz is therefore 330/500 =0.66M
1/2 wavelength (to achieve 180 degree shift) is 0.33M - approx 13"
So, it would be possible to reduce the sound output measured by a dB meter by a good 75% I would guess (6dB) just by extending one leg of the Y pipe.
OK all we need now is for someone with the right audio gear to record the output of an SD at around 7500RPM and look at the spectrum so we can determine the main frequency to be tackled.
This may actually be do-able boys
This is threoretical and assumes the main exhaust frequency is 500Hz.
Speed of sound is approx 330M/S
Wavelength of 500Hz is therefore 330/500 =0.66M
1/2 wavelength (to achieve 180 degree shift) is 0.33M - approx 13"
So, it would be possible to reduce the sound output measured by a dB meter by a good 75% I would guess (6dB) just by extending one leg of the Y pipe.
OK all we need now is for someone with the right audio gear to record the output of an SD at around 7500RPM and look at the spectrum so we can determine the main frequency to be tackled.
This may actually be do-able boys
Post 9 by Twisted Jester,
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Post 10 by Plipton,
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Post 11 by BASH69,
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Post 12 by ShadeTheChangingMan,
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Post 13 by BASH69,
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Post 14 by Plipton,
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Post 15 by Twisted Jester,
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Post 16 by ShadeTheChangingMan,
#16the problem with that is direction and frequency....you'd have to cover over the exit of each pipe and create the out of phase signal at that point to nullify most of the audio. The device would have to be able to respond to level changes instantly and cope with the airflow.
The hardest part would be to cancel the audio coming from other parts of the system. It's much easier to use this technology on audio entering into a (small) space ie: noise cancelling headphones. than it is to reduce noise exiting a device..especially when it's got such a large volume of air movement rather than just audio energy. Prolly far easier to develop a fast electric bike than solve this one imho!
The hardest part would be to cancel the audio coming from other parts of the system. It's much easier to use this technology on audio entering into a (small) space ie: noise cancelling headphones. than it is to reduce noise exiting a device..especially when it's got such a large volume of air movement rather than just audio energy. Prolly far easier to develop a fast electric bike than solve this one imho!
Post 17 by Colonel_Klinck,
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Post 18 by jmann,
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Post 19 by Schnauzer,
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Post 20 by Pig Benis,
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Post 21 by BASH69,
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Post 22 by Pig Benis,
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Post 23 by ShadeTheChangingMan,
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Post 24 by Twisted Jester,
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Post 25 by Twisted Jester,
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Post 26 by Plipton,
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