I absolutely hated how loud my machine was. Was painful just going for a ride. I can honestly say the #1 best upgrade I did was an intercom with headsets. It's an absolute pleasure to drive my X3 now. If I'm by myself I wear the headset just for hearing protection not to mention I can play music through the system as well. With a passenger, conversations at speed are enjoyable & don't require raising one's voice. I do believe a windshield is a must with a headset com system as wind noise at speed can cause issues with the mic. A helmet system probably isn't as sensitive to wind.I will post some of my "noise" findings here and hopefully it helps.
I picked up an XDS RR a few weeks ago and the noise was savage around 5000. Maybe not even so much the noise level as the frequency of the noise. It literally vibrated my head, mostly in my sinuses. I went on a 6 hour ride and was literally in a stunned state for about 2 hours after I got home. Gave me a nasty headache eventually. I ended up around 5000 rpm a lot that day due to the trails we were on. Surprisingly my wife doesnt really notice it nor does it bother her. Which makes me think it is more the frequency than the noise level that sucks for certain people.
So far I have installed the updated muffled air ducts. It does make a difference but not a HUGE improvement. But still good enough I would spend the $ on them again, so worth while in my case.
Next I blocked the intake behind the seat. In my case that made more of a difference than the updated intakes. But the combination of the 2 mods work well together. It is quieter without question. I cancelled out the frequency that was bothering me. I also noticed that the noise lives in a significantly more narrow rpm range. IE when let off the throttle and the rpms drop from say 5500-4500 the noise passes by much more quickly and is less drawn out. Much more enjoyable to drive and it no longer rattles my skull. It is at least at the level of reasonably tolerable now.
I know these things are loud and squeak and rattle, and I can live with that. I know the driveshafts can develope noises and that has started happening. But there are still a few other wtf noises and rattles going on lol. I will continue to update.
From reading posts and doing research it seems pretty obvious that not all fixes work for everyone. There are a bunch of things going on here and 2 cases are not always going to be the same.
I have another rattle going on others experience. Heat shields seem fine. I tried clamping the exaust springs-zero difference made. I will try popping the spark arrestor out tomorrow and see what that does. I will let you guys know how that goes...