This is a tale of failed experiments on GPMINI … don’t read if you don’t like failure!
The plan: quieten GPMINIs interior to reduce the rumble of road noise, and install new speakers to improve the (sub)bass response.
Actions: install loads of Dynamat Extreme on all the panels I can access, and install Kicker KS6.2 speakers which look to have great low frequency performance!
Results: The Kicker KS6.2 speakers are HORRENDOUS! They only stayed in GPMINI one weekend – and that was because I didn’t drive it! There is so much high frequency from them, they’re incredibly harsh and gave me a headache within 5-10 minutes of listening to them. Turning down the treble on the HU didn’t help much, it just made everything sound muddy. I’d selected the Kickers to get more low end – but they didn’t seem any better at that either! So the stock speakers went back in.
I first drove GPMINI with all the Dynamat installed but none of the rear panels back in. It was amazing how LOUD the exhaust noise was – of course there’s two air vents at the back of the MINI that were not covered by the trim piece under the hatch … I stuffed them with foam, and I re-installed the carpet that covers the battery (and has some good thick foam sound deadening on it); that got the exhaust noise under control again.
But I can’t claim any noticeable reduction in road rumble from the tires, due to the Dynamat Extreme. It claims exactly that – to reduce road rumble – but it doesn’t seem to make much difference (and I added 20lb of Dynamat to the car!)
Of course when I add the rear panels back, there might be some further noise reduction, but the Dynamat is no “magic bullet” for quieting GPs!
My next plan is to stick some foam batting to the back of the trim panels before I re-install them – maybe that will help (at least it won’t add much weight!)
As for improving the stereo, I had an idea to install a subwoofer in one rear foam storage tray but I’ve decided now that all this DIY experimentation isn’t good for me – it’s very frustrating when it doesn’t work as I’d hoped! So, time to find an expert …
M&I / GBMINI 
Isn’t part of the draw of the GP the added noise and reduced weight? Granted, 20 lbs is negligible in the grand scheme of things, but isn’t that sacreligous(sp?)?
I have not had the pleasure of driving a GP, so I have nothing to compare to, but I also think the car – at least from what I’ve read thus far – is not really intended as a daily driver per se. This is your daily driver now?
As for improving the sound system, while the GP’s exhaust and engine is a great sound system in its own right, I do like good sounding music when the mood calls.
Not bashing you at all, just curious on this. Good luck!
For some people, reduced weight and added engine/exhaust noise are doubtless part of the appeal.
For GPMINI, changing the driver could save loads more weight than I just added – at the same time, a heavier but skilled driver (not me!) would outperform a light but less-skilled driver.
The GP, like all MINIs, appeals to different owners in different ways – I’m addicted to the power and I love the roar on hard acceleration, but I don’t need noise continually when driving normally.
And yes, GPMINI seems to be my daily driver now … I really should find a new owner for GBMINI!
dynamat will help reduce audible noise from the outside, but much of the road noise you hear is conducted through the suspension and frame. The way to reduce that is a looser suspension and higher profile tires. You’ll have to put on standard brakes and 15-inch wheels if you really want it quiet.
Ian: Wow quite an undertaking from what I see in the pictures. As there are two fundamental ways sound is transmitted: air-borne and structural-borne it would appear that your road noise is making its way up through the suspension and then literally radiating from the car’s body panels. Low frequency air borne sound can only be reduced with mass – so you can assume the Dynamat is working in that area as you as you say its quite heavy, so the assumption is that its structural borne and making all panels such as the suspension towers, firewall and other panels, act like radiators.
You could find some rear seats and a parcel shelf and install them..! 😉
Kidding aside, I’m amazed how much more I hear my JCW exhause when I’ve got the seats folded down, so a GP must be like that squared.
How did you find it on MTTS – I would have thought if you could survive that, you could survive anything!
Ian, how many square feet of Dynamat did you install? Overall it didn’t give you the results you wanted, but did it yield any benefit at all? – Richard
You may want to apply a bit more on the wheel wells. I thoroughly covered mine and it made a considerable difference and was very apparent when I drove GP1717 today as it was considerably louded then GP0154. Guess I will be ordering more dynamat for GP1717.
During MTTS, the luggage in the back of the car made a significant reduction in noise – so that’s one option for me!
The kit was 36sqft of Dynamat Extreme and I used 7 out of 9 sheets, so 28sqft.
Valid points. It is so true about the driver as skill level makes a huge difference. I too would fall under the less skilled category – especially since I learned to drive a manual transmission on my MCS.
I was not criticizing at all… Far from it. The MINI indeed appeals to people for dfferent reasons – none of which are more right or wrong than others. Frankly, I would love to have a second MINI around, but convincing my wife that we as two people, need three cars is a stretch for now.
I really want the new BMW 335i Coupe and then keep my MCS as a weekend and track driver, etc. She’s not on board just yet… I keep working on her though. 🙂
Good luck with that …
Margaret, my wife, is almost opposite, encouraging me to replace one MINI with something else (anything else, in her opinion!)
Ian, Contact Soundown http://www.soundown.com (I think)in Salem. They make engine room kits for boats. Get some 1/2″ sticky backed foam to cap the Dynamat. The lows will still be there but adding some absorbant foam will make a big difference.
c
Foam is only going to stop high frequencies… mass, is the only thing to reduce lows.
Hmmm … what about if I fill the whole back of the car with foam? 😉
Ian, to reduce noise and also have a very unique GP… install a rear seat!
Great post. I was just looking at the benefits of dynamat and wondering what experiences folks had had. How long did it take to do the dynamat (not speakers) install?
The Dynamat install takes time because of cutting pieces to fit. I spent a couple days on it, but only an hour or so at a time. Had to stop whenever I sliced a finger (the Dynamat edging is very sharp!)
Dynamat works well for different types of noise. You can use it sporadically for dampening panel resonance (which is what your photos indicate) and this will cut down on certain frequencies and buzzes that can propagate through out a car. If you want to quiet the car by blocking road noise, exhaust, and or seal in the bass so that the SPL in the vehicle increases, then you have to cover all the panels in and area including sealing up any gaps between pieces of dynamat with strips of dynamat to overlap the joints. This will make the car a lot quieter, especially in the floor pan and wheel wells or wheel arches. I had an old C1500 pick up with a NASCAR sounding exhaust I used as an audio demo vehicle (owned my own audio shop for 15 years); It was sprayed with sound deadener on all panels, floor, and roof, and dynamat extreme on the inside door panels. You could hardly hear the prodigious bass emanating from the 12 inch subs when the truck was sealed up (doors and windows closed). But once the windows were down or the doors opened you were greeted with a flood of sound. Several competition vehicles we did over the years also had dynamat on the roof, floor, sides, firewall, etc… lining the whole interior. SPL was always higher in those cars (any panel that resonates with audio energy is absorbing energy that could other wise be used for moving air and creating sound) and in most cases the audio was barely heard outside when turned all the way up with the were doors closed, even one car that was hitting close to 150 db.
Granted it is costly to do and will add weight, but it can have benefits if you prefer less cabin noise or want to hear the details of the audio system more clearly. And you can save money on amplifier power when you don’t have to overcome so much road noise to hear music while going down the road.