Hi everybody,
 
since a few days ago I am proud owner if a pair of Shure 846s. I have been looking forward to steeping into this league of IEMs for many, many years, you can probably imagine how excited I was to finally listen to them. Unfortunately, my experience with them was a bit of a let-down so far.
 
My previous experiences (all sub 20 $ headphones excluded):
IEMs: Shure 215, 420, 425, Sennheiser IE80s, (probably) Chinese Shure 215 fakes
Cans: lower class Sennheisers mostly, Koss PortaPro, lower class portable AKGs
 
While I am blown away by the details and resolution of the 846s, I am a bit disappointed by the bass impact. Was I expecting too much? I am still struggling to get a perfect seal, at the moment I am using Comply foams. I am not sure if they're maybe a bit too small and I have yet to try out the Shure foams.
 
Another thing I noticed was a very uncomfortable, high frequency rattling noise in my right earphone. It seems to be especially prominent during treble rich sections. On closer inspections, I noticed that the two halves of the shells didn't perfectly align, especially on the right earpiece (I am not allowed to post pictures yet unfortunately). Is this to be expected? For a thousand dollar IEM, this is truly dissapointing.
 
 
It'd be great if some other users could share their experience, especially during the first few days of use. Does the sound quality improve? I am not sure if I should believe in burn-in, but in this case, my hopes for it are high. Also, do your shells fit perfectly snug on each other?

The SE846 only really kick in the sub bass. Doesn't really kick in for all types of music so try a variety of them first. However I've never experienced a high frequency rattling in my pair so it's safe to assume that it's not normal. Nor are my shells unaligned though it's not the smoothest finish. I did however find a variety of issues while listening to them but that was because the music I was listening to was mastered badly. If the rattling is on a specific song and the same time it could be the song and not the earphone. Though if you're really concerned I would pop support a message. Shure customer support is really good so I'm sure you'll be in good hands.

Thank you so much for your quick reply Dulalala!
It is reassuring, although at the same time disappointing, that your sheels do not fit tight either. I would not have thought that of an IEM by Shure in this price range. My 425s seem to be of much higher quality workmanship.
 
The rattling seems to be getting better, but I will keep an ear on it. It happens during listening to pretty high quality FLACs as well, in tracks that I think generally show a very high production quality. It always happens at the same sections, though it's definitely not "in" the music. It would be interesting to know if this at least could be related to a technical issue that will resolve itself during prolonged use or not. Unfortunately, my technical knowledge regarding the 846s is too limited to be sure of that.
 
I'll send a picture of the shells of my pair to Shure to make shure it's alright. I'll post an update as soon as I get news on that.

If you like, you could send me the information for the song and I can test it out to see if the rattling occurs on mine. Also even though the finish on the SE846 is not the best, these things are built like tanks (the metal ones at least).

Thanks a lot for the offer, but it is probably not necessary. I have tested the song(s) with my other equipment (i.e. other DAPs and headphones), and it's definitely not the source that's making problems.
 
Interestingly enough, I have tried the thicker Shure foams yesterday as opposed to the Comply foams that I was using before. In certain songs the rattling is completely gone, in others I have noticed it ever so slightly, yet it was still very disturbing. I am wondering if the tips or the way I am inserting the headpones into my ears might have anything to do with it. Maybe it's an anatomical thing, a loose screw or so maybe?

Now I would have pictures to show the misalignment of the shells, but still no rights to upload them...