If you cut the baffles out then your bike will register around 95 decibles at idle and around 120 decibles revving.
It's kind of loud, but I just pop in my ear plugs when I'm taking long trips.
To give you a comparison on how loud that is keep in mind that a lawnmower registers around 90 decibles, a jet engine registers around 120 decibles and gun shots are around 140-150 decibles.
Well I should add a little more insight so you know the power of sound. You see that I said the debaffled pipes would be around 95 decibles at idle and 120 decibles while revving. So, you say thats about 30 decibles difference, right?
Well, it's not just a number. Hearing loss comes from anything over 85 decibles and your damage depends on how loud something is and the length of exposure.
Decibles are a metric measurement. So, things multiply by tens. If you have something at 90db and another sounds at 120db then keep in mind that the 120db sound is 1,000 times more powerful(louder) than the sound that is 90db.
Ear plugs are recommended
What kind of measuring device did you use? It's important to note that the average "Radio Shack" type meter measures "RMS" and "PEAK".. RMS being an "average level" and Peak being.. well, peaks. It is NOT rated to approximate the human ear.
It's also important to note that it depends on the environment, the road surface, ambient noise (I doubt that the 25 foot measurement was taken indoors, with no ambient sound, and a mix of hard and soft surfaces, etc... etc..) and the testing microphone used. What we're talking about here is written as dB/spl.. decibels of sound pressure level.. "volume", if you like.
That being said.... it IS still an idea of what the noise level truly is.
Using the Cirrus CR 262 meter (borrowed, no I don't own a $1500 sound level meter, lol), with only the screens drilled out of the exhaust, I got a maximum sound pressure level of 109 dB/spl. That reading is NOT "accurate" as it was taken on the side of the street, in a completely uncontrolled environment, approximately 4 feet from the exhaust, in line with the pipe.. where nobody's ear is EVER going to be. However, it's a guideline.
And what Sam said is true.. any sustained noise over 85/90 dB/spl is potentially ear damaging. FFH or earplugs (or both) recommended, however make sure you can still hear a bit of what's going on around you!
If your ears ring, or feel "fuzzy" or "tired" at the end of a ride.. you need protection, you're hurting your ears, and they DON'T RECOVER. once the hairs inside your ear canal are damaged, they're done. They don't grow back.
The "threshold of pain" as described by audio guys is 140dB/spl.. and it's very unpleasant even getting close to that level unprotected.
One last thought.. according to that log scale that was mentioned, once you hit 100dB/spl, it then takes exactly twice as much energy to gain 10 dB.
For example, a 100 watt stereo making 100dB would have to be increased to 200 watts to get 110dB, to 400 watts to get 120dB, and to 800 watts to get 130db. All things considered, I'm not sure there's much for motorcycles that can create 140dB/spl- or I dang sure HOPE there aren't!
