I'll try to keep this painless. If any of you have a decibel meter ($39 at R-shack), could you take a few simple measurements at idle? I'm looking for two measurements from the cabin (5 inches in front of your chest from drivers seat or passenger seat is fine), set the meter to "a" weighted and write that measurement down, then set the meter to "c" weighted and write that down, lastly would be an outside measurement, "c" weighted 5 inches from the side of the muffler. All measurements at idle.

I'm trying to get an idea of the different noise levels of Coopers at idle, from different years and models. Please list which model and year cooper you have and if it is modified. Magazine articles have claimed newer models are quieter, let's see if it is true!

I measured:
In Cabin:
"c" weighted 81 decibels
"a" weighted 59 decibels
outside the car 5" to the side of muffler "c" weighted 98 decibels

 

The title should have read "Got a decibel meter?", it was not meant as a demand that people purchase one...Anybody got a measurement?

 

54 db a 5" from driver's chest
74 db c as above
100 db c 5" from side of muffler

Realistic analog sound level meter (33-2050)

2003 MINI Cooper
OEM manifold
MiniMania Intake
Milltek catback exhaust
Dynamat in the doors.

 

Thanks for the contribution! Considering how many people have told me the "stock oem" exhaust is the quietest option, this is already interesting.

 

If you also want some Gen II measurements, I got:

2008 MCS:

Cabin C: 74
Cabin A: 54
Exhaust C: 67

2007 MC

Cabin C 69
Cabin A: 50 (may have been less, meter only goes down to 50)
Exhaust C: 75

 

Sorry, but there are way to many variables to contribute to any worth-while data. This test would have to be done in a much more controlled environment, with the same equipment, and all conditions the same.

I think the results will vary greatly because of this.

-Cody

 

Simply not true, while it might not be perfect, it will certainly be worthwhile. Of course there is going to be some user error and equipment that is not perfectly calibrated, but with enough data, you at least get the big picture. Decibels are not rocket science, and with proximity somewhat accounted for the numbers can asnwer questions that the very poor magazine reviews do not.

We don't need this to be perfect to within .1 db, within 2-3 db and only using idle will certainly give a good idea of what is going on before tire noise is factored (too big of a variable). I think recording the rpm at idle is worth noting, but I wanted to keep this pretty simple.

I have a pretty good idea about the science of sound, this will give us better data than people stuffing their cars with 4 layers of Dynamat and swearing that it acts as "soundproofing".

Therre is no point to being negative about an actual "new topic" that up until this thread, could not be found with the search engine...maybe I should have asked "which winter tires for my Mini?" :-)

 

Thanks for taking the time to make some measurements...the shocker here is that in the 2008 MCS the cabin is louder than being 5 inches away from the exhaust pipe. Usually the cabin is down about 20-25db from the close proximity tail pipe measurement. What kind of meter was used?

 

Forgot to mention I have some Dynamat in the front doors - added it to the post.

 

I have cascade in the doors and their lead septum in the boot and floor...total reduction achieved after an installer who worked with and distributed Cascade completed the installation? about 1db!...It appears the low freqs have an easy time with windows and basic door seals.

If I open my side door, and sit on the back seat ( but without touching the back of the seat) and give the rear "seat backs" a hard "wack! the bass freqs ring like a drum. I think it is possible while the rear seat can surely help quell exhaust drone by being "up " it may also sympathetically resonate in some coopers and add some bass boom (just like doors/panels might without an adhesive damper attached). If I pop one of the seat backs off it's latch, but leave it in the up position (resting on the latch) it removes this "boom" effect. I need to look at it more, but calming this "boom" may help reduce the some sound fatigue of hitting pot holes on a lousy stretch of road (at least on my ears!).

I called endless installers who sold/installed sound control products, none of them would guarantee even a single decibel of reduction...this after claims of how "coffin quiet" my car would be. It was funny to see them recoil and backpedal when asked to back up their claims with a decibel reduction guarantee...and this is with them installing the product that they were selling/hyping.

 

I'm not entirely convinced by that, I think I may had it on the wrong weighting. It was a Radio Shack digital sound meter.

 

I guess that's where I was going, I think I agree...I still give much props for the effort...anything that makes a new topic and info not previously on this site, is worth the trial and error.

 

I measured the MCS again, and I think my previous measurement was good. This time I got 77dbc, but it didn't change much if at all when I changed from a to c. So either the meter is doing something funky, or I got it right both times. That would also show that the measurement is somewhat variable, by 10db. Last time the MCS was barely warmed up, this time he'd just come down the freeway for 10 min.

 

Did you check the exhaust measurement again, the cabin or both? the cabin measurement seemed about right for c weighted (70-80dbc), but the exhaust c -weighted was really quiet...surprising even, I'd love to have my exhaust tamed to that level.