Triumph 765 RS exhaust noise test comparison - standard, EU spec Arrow and US spec Arrow

Triumph 765 RS exhaust noise test comparison - standard, EU spec Arrow and US spec Arrow.

This is a noise test comparison to show the differences between the standard exhaust, the Euro 4 spec Arrow and the US spec Arrow (with and without baffle).

Because microphones attenuate the recorded sounds to the same level, I have tried to do a reasonably scientific test to show the actual noise levels of each of the above exhausts. This has thrown up some interesting anomalies, specifically with the baffle in the US spec Arrow. With the baffle installed, below 9000rpm the noise levels are significantly reduced, but above that the noise level is substantially INCREASED compared to without the baffle. This is likely to be caused by the effect the baffle has on the pressure waves at high rpm.

It should be noted that every 3dB represents a DOUBLING of sound intensity.

Noise test equipment: TES 1351 sound level meter (calibrated same day).

All static tests were carried out at a distance of 60cm with the ride-by done at 310cm.

Standard exhaust:
Weight: 6.4kg
Idle: 76.4dB
3000rpm: 86.2dB
6000rpm: 96.0dB
9000rpm: 103.2dB
12000rpm: 109.2dB
2nd gear WOTto 12000rpm ride-by: 106.3dB

Euro 4 Spec Arrow:
Weight: 5.3kg
Idle: 78.0dB
3000rpm: 86.8dB
6000rpm: 97.1dB
9000rpm: 105.5dB
12000rpm: 111.6dB
2nd gear WOTto 12000rpm ride-by: 107.8dB

US Spec Arrow (WITH baffle)::
Weight: 4.9kg
Idle: 79.3dB
3000rpm: 87.3dB
6000rpm: 96.7dB
9000rpm: 105.4dB
12000rpm: 112.3dB
2nd gear WOTto 12000rpm ride-by: 108.5dB

US 4 Spec Arrow(WITHOUT baffle)::
Weight: 4.9kg
Idle: 85.9dB
3000rpm: 88.7dB
6000rpm: 98.2dB
9000rpm: 104.0dB
12000rpm: 110.6dB
2nd gear WOTto 12000rpm ride-by: 105.5dB