I hope so. If you can't, there might be something wrong with your hearing.

My point was that a 5 db increase from 87 to 92 doesn't sound like the sound more than doubled. It's five linear steps up the scale that humans perceive as a 5%-6% increase in sound level.

Almost. Power doubles roughly every 3 db. So from 0 db to 3 db doubles the power. 0 db to 6 db quadruples it. Etc.

Guess that's why I told you yours was the best sounding twin at a PIR track day.

I should let you hear the exhaust that doesn't pass sound at PIR some time, pretty amazing how much a single 5" canister muffler reduces the volume.

Agreed! :D

Don't be fooled by decibels.

Moving twice the distance from the original measurement reduces DB by 6.

If the original measurement was taken at 6 inches from the pipe, and you get 83 DB then you get:

1 ft = 77 DB
2 ft = 71 DB
4 ft = 65 DB
8 ft = 59 DB

Of course, if that was taken at 4ft then you get a relatively good assessment. Still, 8ft goes to 77, 16ft goes to 71

dB are logarithmic, so this can be a very deceiving stat to look for. I would at all costs avoid it when determining what exhaust to use, purely because there is no standard by which everyone measures the exhaust from in terms of distance.

Although I totally agree with the rest of your statement the last line is not correct!
The measurement of exhaust sound levels in covered under the SAE Standard J986. It is very clear how and where the measurements are supposed to be taken.


Now, having said that just how many places know/do this is a totally different matter!


http://standards.sae.org/j986_201311/


http://media.caranddriver.com/images...s-original.jpg

Fair enough. But yeah, impossible to know if they actually do it or not. That's why these results can be so misleading! it is a shame it isn't easier to just listen to all your choices, in person.

Lol my bike is 105 dB... Guess that's why my hearing is $hit

I know perfectly well what happened to my hearing!

Of course things like this will be entirely subjective but fwiw - I have never had an aftermarket exhaust before, I am someone with sensitive hearing, and (in general) I hate loud noises.

I purchased a Tomei type 60S (which I believe is rated at 91 - 93db with an all-stock set up except for the catback), and I've had it installed for a few months now - and I love it. I think it is just loud enough that it makes it fun, and exciting to open up the throttle, and it compliments the car well in terms of getting a good amount of feedback when you're driving.

I was really worried that it would be too loud, and admittedly the cold starts are, but I love everything about it. It's not going to be obnoxious, or piss anyone off as long as you're not trying to drive like an ass, and even then it probably isn't going to be louder than the average motorcyclist accelerating.

I'm also not sure if this was just from getting used to the exhaust, or if this is the case with all exhausts or not - but I genuinely felt like my exhaust quieted down a bit after 3 - 4 weeks of driving after getting it installed.

I think you'll be more than alright going with a 83db rated exhaust - if the concern is your comfort while driving, you'll have the option of doing a sound tube delete which would probably quiet down the in-cabin noise a bit, but really - I think you'll be quite happy with a new exhaust, and you won't even notice any issue(s) with the sound (or maybe you'll even want it to be a bit louder) after a few weeks of DDing it.

GL :thumbsup:

The proper way test if an exhaust is too loud is

to floor it up and down your street in 1st gear and only use engine breaking

if no one comes out bitching then your good to go

if someone comes out bitching tell them to FUCK OFF!!!

83dB is pretty quiet, it also depends on how it is measured, at what angle and distance from the tip, what speed/RPM range etc. IIRC my dads stock Z4M was measured at 96dB at WOT from a distance of 10 feet parallel to the car, his Caterham is significantly louder than the Z4M and requires ear protection when driving. I am willing to bet the Milltek is much quieter than both those cars in real world circumstances when driving.