I get a very good fit & seal with the ZSR; however with the ZSA I just couldn't. The ZSA would actually fall out with even a slight movement of my jaw.
I decided to see if using double flange eartip would help. They do - I get a good fit & seal. The ones I got :
- are not longer then the stock tips.
- do not insert deeper than the stock tips.
- have a wider bore 5mm.
I got them from the Trig Rain Official Store on AE.
Link:
https://www.aliexpress.com/item/5mm-Original-Two-Layer-Silicone-In-Ear-Earphone-Earbuds-Ear-pads-covers-Eartips-Replacement-Headphone-Earplugs/32700128989.html
Pretty cheap, so if you have a similar prob try them out. The store allows you to choose diff sizes in the same order. I use the L ones, see pic below. ( Wonder what happens if you place a weird order like 5 L and 1 M, LOL ). The build quality of the eartips isn't that good.
I have also ordered the TENNMAK wide-bore eartips, btw.
I now use the ZSA with the KZ type-C DAC. Sounds much better, I did not care too much for the ZSA SQ before - it still doesn't come close to the ZSR. I still have to try the Slater ZSA mod, with micropore tape.
Recently I've seen ZSR listings for just 16.99 USD with AE Std shipping.
Stock vs Double Flange: