I would seriously try to see if you could make a mod of some sort to allow the Xelastec to fit, maybe take some black tape and made the nozzle wider. Or even try to see if Xelastec sells more than one nozzle size.Thanks for reaching out. For me it's very much the nozzle and not at all the shell. The problem is very much that the nozzle (plus any tip I've tried) is too wide/thick to enable a comfortable DEEP insertion. I'm using foam tips mainly (as per your recommendation months ago on this site) as you can roll these tips into a small shape and then push them in deeply before they expand once deep within the ear canal. However, even these have a few issues... 1) even with a small size tip these are still too large (once expanded) and you can feel a build up of pressure after just 30 minutes; 2) The (foam) tips always seem to slide out after a while (from the 'deep' insertion position, to a more normal (shallower) insertion position) leading to the shell no longer touching much of my skin and therefore negating much of the benefit of the BCD, this then leads to me having to constantly try and push back in (which starts to hurt after a few times as consistently rubbing the ear canal or whatever); 3) I sometimes need to remove and re-insert the IEMs on a regular basis (when I need to stop listening to do something else and then come back to listen a while later) and I find that more I insert deeply the more I'm aggravating the areas/skin deep in the ear canal, to the point that I can feel a bruising/raw pain like my ears are bleeding (that don't actually bleed). I wonder if there are much softer foams that can help with this last point?? I'm using comply currently.
Whilst I appreciate that other IEMs might not need a deep insertion as they won't have BCD technology, I can't get away from how comfortable my final A8000s are. These do not need a deep insertion, I simply put a large comply foam tip on them and insert them with shallow insertion and they stay effortlessly in place for 10 hours with no discomfort whatsoever! Come to think of it, I'm sure the small size of the A8000 shell makes more contact with my skin than the universal MEST shell does due to it tucking in tighter in the ear!
I did try the Xelastic tips but I found that these keep coming off the IEM and getting stuck deep in my ear canal. I can't recommend anybody else do this given my experience (although I know others don't have the same problem).
I really appreciate your comments about the difficulties faced making the custom MEST and I do applaud the efforts that UM have made to bring something like that to the market. I think, ultimately, people like me buy the universal version as they want to try the MEST sound without the additional expense of going custom but don't realise that they are getting a truly inferior experience (my opinion but based on your comments of better sound quality and obvious comfort issues I've encountered).
All of these issues that you're having would literally be fixed with Xelastec. Seriously I can get my Voyager 14 so deep in my ear and it STAYS there for 20 hours if I wanted. My v14 universal get as deep as customs if I do the ear pull open mouth insertion.
I use medium size Xelastec, they are a MIRACLE. My Dekoni and comly also irritate my ears idk how it's even possible, after 2 hours it feels like a plastic is rubbing on my ear, but it's a soft foam? It makes zero sense. For me I own 35+ sets of tips, like Unique Melody said I stopped my entire tip search when I found Xelastec, they are absolutely mindblowingly comfortable and perfect.
They're so good I'd take a 20% hit on sound quality just not to deal with other tips ever again.
I've also learned from previous mistakes I've made in shopping that you should always always always buy the top of the line in everything you buy, I have regretted not buying TOTL every single time, I can't think of once where I was like "I should of bought the lower end model" sure now that doesn't mean buy Utopias, Bugatti or Oriollus Trailli iems, but I have learned my lesson in audio as well. Instead of working my way up from 20 bucks to 3000 for iems I should of just went with custom mest from the beginning, lot of lost money and time trying to save money and time, sometimes its better just to spend an extra dime and you'll get limes instead of lemons.