As I mentioned in a different thread, soon after getting my OPN’s (online) I ditched the cheap-ish silicon domes for memory foam tips: Comply comfort 100’s specifically (Comply™ 100 Series | Foam Ear Tips for Etymotic, Westone, Isotunes & More – Comply Foam). While these are not vented, you can poke a few holes through them with a pin if you want (IMO it made a small difference as far as the plugged feeling you get with any tip that fills your ear canal. However after a few days of use, the plugged feeling diminished and now I don’t notice at all. Also at first I thought my voice sounded strange. Now I think I’m just hearing what it really sounds like, and it sounds fine.). As far as the sound - vast improvement. There’s a reason many in ear monitor’s used by musicians utilize these tips. Before I used these, feedback was a major, almost deal breaking issue. Also every aid I’ve tried over 20+ years had feedback problems. But with these tips, I can rest my head on a pillow or put my hand or anything right over my ear - no feedback, not even a hint, even at max volume (which I never use except to test feedback). And over the ear sound isolating head phones sound awesome - which because of feedback were unusable before. The memory foam conforms to the hearing canal (I’m using the large size) so it is in effect a custom fit, and never comes out unless I give it a good tug. It feels more secure than the silicon tips with the wire holder ever did.
As far as how to put these on, I first remove the plastic wire holder (no longer needed) from the speaker tip, then reverse the foam tip so the indent is facing out. IMO this is more comfortable and allows the speaker to seat deeper in the ear but YMMV. With the 100’s it’s a tight fit at first, but the OPN speaker will slide inside the Comply 100 tube, it takes a bit of a push the first time. And once on there is no reason to take it off. My first set of foam tips are still going strong after 3 weeks of constant use. I’m not sure how long each tip will last but a month or two seems reasonable. And at $17 for four pair on Amazon totally worth it.
Also I’m not done experimenting. Right now I have #2 size speaker wire but asked BH to send some #3 size. Because of the deeper fit these tips allow, I think a longer wire might be a tad more comfortable. Then I might remove (cut off) the wax guard with sits at the very end of the speaker tip. I’ve had a few problems with this particular wax guard. First it gets plugged (as you would expect) and replacing the guard is a hassle and these little things - like every other hearing aid accessory - is way over priced (yes I got a free supply with the aids from BH, but only about ten, so these won’t last long). Second, without the silicon tips which normally sit over and around the wax guard, the wax guard is somewhat exposed and it has a sharp-ish edge to it. This hasn’t caused problems for me with the memory foam tips, but at the same time it seems necessary. By removing this guard, which is in effect a nipple at the end of the speaker tip, the speaker element itself can now be that much closer to the opening of the foam tip and also my ear drum. And closer seems to provide better sound, in particular base response. As for a substitute wax guard, I’m going to cover the now exposed speaker opening with 3M micropore tape, which allows air to pass through and so should be sonically transparent, but is remarkably water/liquid resistant (I tape cuts on feet with this before surfing for a few hours, and it stays on under those circumstances so should be good here). It’s a lot like gore-tex in that respect. Anyway this is a still a future experiment, but going with these memory foam tips has certainly solved the feedback issue with better overall sound for me.